diff --git a/ifttt/ifttt.php b/ifttt/ifttt.php
index 6d4f402c..faaea2ca 100644
--- a/ifttt/ifttt.php
+++ b/ifttt/ifttt.php
@@ -180,5 +180,5 @@ function ifttt_message($uid, $item)
 		$link = hash('ripemd128', $item['msg']);
 	}
 
-	Post\Delayed::add($link, $post, Worker::PRIORITY_MEDIUM, Post\Delayed::PREPARED);
+	Post\Delayed::add($link, $post, Worker::PRIORITY_MEDIUM, Post\Delayed::UNPREPARED);
 }
diff --git a/mailstream/mailstream.php b/mailstream/mailstream.php
index 71b123ad..ad28c18e 100644
--- a/mailstream/mailstream.php
+++ b/mailstream/mailstream.php
@@ -416,7 +416,7 @@ function mailstream_send(string $message_id, array $item, array $user): bool
 						 '$upstream' => DI::l10n()->t('Upstream'),
 						 '$local' => DI::l10n()->t('Local'),
 						 '$item' => $item]);
-		mailstream_html_wrap($mail->Body);
+		$mail->Body = mailstream_html_wrap($mail->Body);
 		if (!$mail->Send()) {
 			throw new Exception($mail->ErrorInfo);
 		}
@@ -437,7 +437,8 @@ function mailstream_send(string $message_id, array $item, array $user): bool
  * bbcode's output suitable for transmission, we try to break things
  * up so that lines are about 200 characters.
  *
- * @param string $text text to word wrap - modified in-place
+ * @param string $text text to word wrap
+ * @return string wrapped text
  */
 function mailstream_html_wrap(string &$text)
 {
@@ -446,6 +447,7 @@ function mailstream_html_wrap(string &$text)
 		$lines[$i] = preg_replace('/ /', "\n", $lines[$i], 1);
 	}
 	$text = implode($lines);
+        return $text;
 }
 
 /**
diff --git a/retriever/retriever.php b/retriever/retriever.php
index 977ed49a..9370271c 100644
--- a/retriever/retriever.php
+++ b/retriever/retriever.php
@@ -6,10 +6,12 @@
    * Author: Matthew Exon <http://mat.exon.name>
    */
 
+use Friendica\App;
 use Friendica\Core\Addon;
 use Friendica\Core\Hook;
 use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
+use Friendica\Core\Session;
 use Friendica\Core\System;
 use Friendica\Content\Text\HTML;
 use Friendica\Content\Text\BBCode;
@@ -27,6 +29,8 @@ use Friendica\DI;
  * @brief Installation hook for retriever plugin
  */
 function retriever_install() {
+	Logger::debug('Install retriever');
+
 	Hook::register('addon_settings', 'addon/retriever/retriever.php', 'retriever_addon_settings');
 	Hook::register('addon_settings_post', 'addon/retriever/retriever.php', 'retriever_addon_settings_post');
 	Hook::register('post_remote', 'addon/retriever/retriever.php', 'retriever_post_remote_hook');
@@ -35,11 +39,11 @@ function retriever_install() {
 
 	if (DI::config()->get('retriever', 'dbversion') == '0.14') {
 		if (!DBA::e("ALTER TABLE `retriever_rule` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci") ||
-		    !DBA::e("ALTER TABLE `retriever_item` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci") ||
 		    !DBA::e("ALTER TABLE `retriever_item` MODIFY `item-uri` varbinary(255) NOT NULL") ||
-		    !DBA::e("ALTER TABLE `retriever_resource` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci") ||
+		    !DBA::e("ALTER TABLE `retriever_item` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci") ||
 		    !DBA::e("ALTER TABLE `retriever_resource` MODIFY `url` varbinary(700) NOT NULL") ||
 		    !DBA::e("ALTER TABLE `retriever_resource` MODIFY `redirect-url` varbinary(700) NOT NULL")) {
+		    !DBA::e("ALTER TABLE `retriever_resource` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci") ||
 			Logger::warning('Unable to update database tables: ' . DBA::errorMessage());
 			return;
 		}
@@ -63,6 +67,8 @@ function retriever_install() {
  * @brief Uninstallation hook for retriever plugin
  */
 function retriever_uninstall() {
+	Logger::debug('Uninstall retriever');
+
 	Hook::unregister('addon_settings', 'addon/retriever/retriever.php', 'retriever_addon_settings');
 	Hook::unregister('addon_settings_post', 'addon/retriever/retriever.php', 'retriever_addon_settings_post');
 	Hook::unregister('post_remote', 'addon/retriever/retriever.php', 'retriever_post_remote_hook');
@@ -73,19 +79,19 @@ function retriever_uninstall() {
 }
 
 /**
- * @brief Module hook for retriever plugin
- *
- * TODO: figure out what this should be used for
+ * This is a statement rather than an actual function definition. The simple
+ * existence of this method is checked to figure out if the addon offers a
+ * module.
  */
 function retriever_module() {}
 
 /**
  * @brief Admin page hook for retriever plugin
  *
- * @param App $a App object (by ref)
+ * @param App $a App object (unused)
  * @param string $o HTML to append content to (by ref)
  */
-function retriever_addon_admin(&$a, &$o) {
+function retriever_addon_admin(App $a, string &$o) {
 	$template = Renderer::getMarkupTemplate('admin.tpl', 'addon/retriever/');
 
 	$downloads_per_cron = DI::config()->get('retriever', 'downloads_per_cron');
@@ -137,7 +143,7 @@ $retriever_item_count = 0;
  *
  * @param int $max_items Maximum number of items to retrieve in this call
  */
-function retriever_retrieve_items($max_items) {
+function retriever_retrieve_items(int $max_items) {
 	global $retriever_item_count;
 
 	$retriever_schedule = array(array(1,'minute'),
@@ -183,7 +189,7 @@ function retriever_retrieve_items($max_items) {
  *
  * @param int $max_items Maximum number of items to retrieve in this call
  */
-function retriever_clean_up_completed_resources($max_items) {
+function retriever_clean_up_completed_resources(int $max_items) {
 	// TODO: figure out how to do this with DBA module
 	$r = DBA::p("SELECT retriever_resource.`id` as resource, retriever_item.`id` as item FROM retriever_resource, retriever_item, retriever_rule WHERE retriever_item.`finished` = 0 AND retriever_item.`resource` = retriever_resource.`id` AND retriever_resource.`completed` IS NOT NULL AND retriever_item.`contact-id` = retriever_rule.`contact-id` AND retriever_item.`item-uid` = retriever_rule.`uid` LIMIT $max_items");
 	if (!DBA::isResult($r)) {
@@ -236,7 +242,7 @@ function retriever_tidy() {
  *
  * @param array $resource The row from the retriever_resource table
  */
-function retrieve_dataurl_resource($resource) {
+function retrieve_dataurl_resource(array $resource) {
 	if (!preg_match("/date:(.*);base64,(.*)/", $resource['url'], $matches)) {
 		Logger::warning('retrieve_dataurl_resource: resource ' . $resource['id'] . ' does not match pattern');
 	} else {
@@ -254,7 +260,7 @@ function retrieve_dataurl_resource($resource) {
  *
  * @param array $resource The row from the retriever_resource table
  */
-function retrieve_resource($resource) {
+function retrieve_resource(array $resource) {
 	$components = parse_url($resource['url']);
 	if (!$components) {
 		Logger::warning('retrieve_resource: URL ' . $resource['url'] . ' could not be parsed');
@@ -321,7 +327,7 @@ function retrieve_resource($resource) {
  * @param boolean $create Whether to create a new configuration if none exists already
  * @return array The row from the retriever_rule database for this configuration
  */
-function get_retriever_rule($contact_id, $uid, $create) {
+function get_retriever_rule(string $contact_id, string $uid, bool $create) {
 	$retriever_rule = DBA::selectFirst('retriever_rule', [], ['contact-id' => intval($contact_id), 'uid' => intval($uid)]);
 	if ($retriever_rule) {
 		$retriever_rule['data'] = json_decode($retriever_rule['data'], true);
@@ -340,7 +346,7 @@ function get_retriever_rule($contact_id, $uid, $create) {
  * @param array $retriever_item Row from the retriever_item table
  * @return array Item that was found, or undef if no item could be found
  */
-function retriever_get_item($retriever_item) {
+function retriever_get_item(array $retriever_item) {
 	$item = Post::selectFirst([], ['uri' => $retriever_item['item-uri'], 'uid' => intval($retriever_item['item-uid']), 'contact-id' => intval($retriever_item['contact-id'])]);
 	if (!DBA::isResult($item)) {
 		Logger::warning('retriever_get_item: no item found for uri ' . $retriever_item['item-uri']);
@@ -355,7 +361,7 @@ function retriever_get_item($retriever_item) {
  * @param int $retriever_item_id ID of the retriever item corresponding to this resource
  * @param array $resource The full details of the completed resource
  */
-function retriever_item_completed($retriever_item_id, $resource) {
+function retriever_item_completed(string $retriever_item_id, array $resource) {
 	Logger::debug('retriever_item_completed: id ' . $retriever_item_id . ' url ' . $resource['url']);
 
 	$retriever_item = DBA::selectFirst('retriever_item', [], ['id' => intval($retriever_item_id)]);
@@ -382,7 +388,7 @@ function retriever_item_completed($retriever_item_id, $resource) {
  *
  * @param array $resource The full details of the completed resource
  */
-function retriever_resource_completed($resource) {
+function retriever_resource_completed(array $resource) {
 	Logger::debug('retriever_resource_completed: id ' . $resource['id'] . ' url ' . $resource['url']);
 	foreach (DBA::selectToArray('retriever_item', ['id'], ['resource' => intval($resource['id'])]) as $retriever_item) {
 		retriever_item_completed($retriever_item['id'], $resource);
@@ -395,7 +401,7 @@ function retriever_resource_completed($resource) {
  * @param array $retriever The row from the retriever_rule table for the contact
  * @param int $num The number of existing items to queue for retrieval
  */
-function apply_retrospective($retriever, $num) {
+function apply_retrospective(array $retriever, int $num) {
 	foreach (Post::selectToArray([], ['contact-id' => intval($retriever['contact-id'])], ['order' => ['received' => true], 'limit' => $num]) as $item) {
 		Item::update(['visible' => 0], ['id' => intval($item['id'])]);
 		foreach (DBA::selectToArray('retriever_item', [], ['item-uri' => $item['uri'], 'item-uid' => $item['uid'], 'contact-id' => $item['contact-id']]) as $retriever_item) {
@@ -414,7 +420,7 @@ function apply_retrospective($retriever, $num) {
  *
  * TODO: This queries then inserts.  It should use some kind of lock to avoid requesting the same resource twice.
  */
-function retriever_on_item_insert($retriever, &$item) {
+function retriever_on_item_insert(array $retriever, array &$item) {
 	if (!$retriever || !$retriever['id']) {
 		Logger::info('retriever_on_item_insert: No retriever supplied');
 		return;
@@ -453,7 +459,7 @@ function retriever_on_item_insert($retriever, &$item) {
  * @param boolean $binary Specifies if this download should be done in binary mode
  * @return array The created resource
  */
-function add_retriever_resource($url, $uid, $cid, $binary = false) {
+function add_retriever_resource(string $url, string $uid, string $cid, bool $binary = false) {
 	Logger::debug('add_retriever_resource: url ' . $url . ' uid ' . $uid . ' contact-id ' . $cid);
 
 	$scheme = parse_url($url, PHP_URL_SCHEME);
@@ -501,7 +507,7 @@ function add_retriever_resource($url, $uid, $cid, $binary = false) {
  * @param array $resource Resource that the item needs to wait for.  This must have already been stored in the database.
  * @return int ID of the retriever item that was created, or the existing one if present
  */
-function add_retriever_item($item, $resource) {
+function add_retriever_item(array $item, array $resource) {
 	Logger::debug('add_retriever_item: ' . $resource['url'] . ' for ' . $item['uri'] . ' ' . $item['uid'] . ' ' . $item['contact-id']);
 
 	if (!array_key_exists('id', $resource) || !$resource['id']) {
@@ -528,7 +534,7 @@ function add_retriever_item($item, $resource) {
  * @param array $resource The completed resource
  * @return string Character encoding, e.g. "utf-8" or "iso-8859-1"
  */
-function retriever_get_encoding($resource) {
+function retriever_get_encoding(array $resource) {
 	$matches = array();
 	if (preg_match('/charset=(.*)/', $resource['type'], $matches)) {
 		return trim(array_pop($matches));
@@ -543,7 +549,7 @@ function retriever_get_encoding($resource) {
  * @param DOMDocument $doc Input to the XSLT template
  * @return DOMDocument Result of applying the template
  */
-function retriever_apply_xslt_text($xslt_text, $doc) {
+function retriever_apply_xslt_text(string $xslt_text, DOMDocument $doc) {
 	if (!$xslt_text) {
 		Logger::info('retriever_apply_xslt_text: empty XSLT text');
 		return $doc;
@@ -566,7 +572,7 @@ function retriever_apply_xslt_text($xslt_text, $doc) {
  * @param array &$item Item to be in which to store the new body (by ref).  This may or may not be already stored in the database.
  * @param array $resource Newly completed resource, which should be text (HTML or XML)
  */
-function retriever_apply_dom_filter($retriever, &$item, $resource) {
+function retriever_apply_dom_filter(array $retriever, array &$item, array $resource) {
 	Logger::debug('retriever_apply_dom_filter: applying XSLT to uri ' . $item['uri'] . ' uid ' . $item['uid'] . ' contact ' . $item['contact-id']);
 
 	if (!array_key_exists('include', $retriever['data']) && !array_key_exists('customxslt', $retriever['data'])) {
@@ -610,7 +616,7 @@ function retriever_apply_dom_filter($retriever, &$item, $resource) {
  *
  * @param array $resource The resource containing the text content
  */
-function retriever_load_into_dom($resource) {
+function retriever_load_into_dom(array $resource) {
 	$encoding = retriever_get_encoding($resource);
 	$content = mb_convert_encoding($resource['data'], 'HTML-ENTITIES', $encoding);
 	$doc = new DOMDocument('1.0', 'UTF-8');
@@ -630,7 +636,7 @@ function retriever_load_into_dom($resource) {
  * @param array $retriever The retriever configuration for this contact
  * @return DOMDocument New DOM document containing only the desired content
  */
-function retriever_extract($doc, $retriever) {
+function retriever_extract(DOMDocument $doc, array $retriever) {
 	$params = array('$spec' => $retriever['data']);
 	$extract_template = Renderer::getMarkupTemplate('extract.tpl', 'addon/retriever/');
 	$extract_xslt = Renderer::replaceMacros($extract_template, $params);
@@ -652,7 +658,7 @@ function retriever_extract($doc, $retriever) {
  * @param array $resource Completed resource which contains the text in the DOM document
  * @return DOMDocument New DOM document with global URLs
  */
-function retriever_globalise_urls($doc, $resource) {
+function retriever_globalise_urls(DOMDocument $doc, array $resource) {
 	$components = parse_url($resource['redirect-url']);
         if (!array_key_exists('scheme', $components) || !array_key_exists('host', $components) || !array_key_exists('path', $components)) {
 		return $doc;
@@ -671,7 +677,7 @@ function retriever_globalise_urls($doc, $resource) {
  *
  * @param array $item Row from the item table
  */
-function retriever_get_body($item) {
+function retriever_get_body(array $item) {
 	if (!array_key_exists('uri-id', $item) || !$item['uri-id']) {
 		// item has not yet been stored in database
 		return $item['body'];
@@ -699,7 +705,7 @@ function retriever_get_body($item) {
  * @param array &$item Item in which to set the body (by ref).  This may or may not be already stored in the database.
  * @param string $body New body content
  */
-function retriever_set_body(&$item, $body) {
+function retriever_set_body(array &$item, string $body) {
 	$item['body'] = $body;
 	if (!array_key_exists('id', $item) || !$item['id']) {
 		// item has not yet been stored in database
@@ -713,7 +719,7 @@ function retriever_set_body(&$item, $body) {
  *
  * @param array &$item Item to be searched for images and updated (by ref).  This may or may not be already stored in the database.
  */
-function retrieve_images(&$item) {
+function retrieve_images(array &$item) {
 	if (!DI::config()->get('retriever', 'allow_images')) {
 		return;
 	}
@@ -751,7 +757,7 @@ function retrieve_images(&$item) {
  *
  * @param array &$item Row from the item table (by ref)
  */
-function retriever_check_item_completed(&$item)
+function retriever_check_item_completed(array &$item)
 {
 	$waiting = DBA::selectFirst('retriever_item', [], ['item-uri' => $item['uri'], 'item-uid' => intval($item['uid']), 'contact-id' => intval($item['contact-id']), 'finished' => 0]);
 	Logger::debug('retriever_check_item_completed: item ' . $item['uri'] . ' ' . $item['uid'] . ' '. $item['contact-id'] . ' waiting for resources');
@@ -770,7 +776,7 @@ function retriever_check_item_completed(&$item)
  * @param array &$item Row from the item table (by ref)
  * @param array $resource The resource that has just been completed
  */
-function retriever_apply_completed_resource_to_item($retriever, &$item, $resource) {
+function retriever_apply_completed_resource_to_item(array $retriever, array &$item, array $resource) {
 	Logger::debug('retriever_apply_completed_resource_to_item: retriever ' . ($retriever ? $retriever['id'] : 'none') . ' resource ' . $resource['url'] . ' plink ' . $item['plink']);
 	if (strpos($resource['type'], 'image') !== false) {
 		retriever_transform_images($item, $resource);
@@ -796,7 +802,7 @@ function retriever_apply_completed_resource_to_item($retriever, &$item, $resourc
  *
  * TODO: split this into two functions, one to store the image, the other to change the item body
  */
-function retriever_transform_images(&$item, $resource) {
+function retriever_transform_images(array &$item, array $resource) {
 	if (!$resource['data']) {
 		Logger::info('retriever_transform_images: no data available for ' . $resource['id'] . ' ' . $resource['url']);
 		return;
@@ -838,13 +844,13 @@ function retriever_transform_images(&$item, $resource) {
  *
  * @param App $a The App object
  */
-function retriever_content($a) {
-	if (!local_user()) {
+function retriever_content(App $a) {
+	if (!Session::getLocalUser()) {
 		$a->page['content'] .= "<p>Please log in</p>";
 		return;
 	}
 	if (isset(DI::args()->getArgv()[1]) and DI::args()->getArgv()[1] === 'help') {
-		$feeds = DBA::selectToArray('contact', ['id', 'name', 'thumb'], ['uid' => local_user(), 'network' => 'feed']);
+		$feeds = DBA::selectToArray('contact', ['id', 'name', 'thumb'], ['uid' => Session::getLocalUser(), 'network' => 'feed']);
 		for ($i = 0; $i < count($feeds); ++$i) {
 			$feeds[$i]['url'] = DI::baseUrl()->get(true) . '/retriever/' . $feeds[$i]['id'];
 		}
@@ -857,13 +863,13 @@ function retriever_content($a) {
 	}
 	if (isset(DI::args()->getArgv()[1])) {
 		$arg1 = DI::args()->getArgv()[1];
-		$retriever_rule = get_retriever_rule($arg1, local_user(), false);
+		$retriever_rule = get_retriever_rule($arg1, Session::getLocalUser(), false);
 		if (!$retriever_rule) {
 			$retriever_rule = ['id' => 0, 'data' => ['enable' => 0, 'modurl' => '', 'pattern' => '', 'replace' => '', 'images' => 0, 'storecookies' => 0, 'cookiedata' => '', 'customxslt' => '', 'include' => '', 'exclude' => '']];
 		}
 
 		if (!empty($_POST["id"])) {
-			$retriever_rule = get_retriever_rule($arg1, local_user(), true);
+			$retriever_rule = get_retriever_rule($arg1, Session::getLocalUser(), true);
 			$retriever_rule['data'] = array();
 			foreach (array('modurl', 'pattern', 'replace', 'enable', 'images', 'customxslt', 'storecookies', 'cookiedata') as $setting) {
 				if (empty($_POST['retriever_' . $setting])) {
@@ -966,10 +972,10 @@ function retriever_content($a) {
 /**
  * @brief Hook that adds the retriever option to the contact menu
  *
- * @param App $a The App object
+ * @param App $a The App object (by ref)
  * @param array $args Contact menu details to be filled in (by ref)
  */
-function retriever_contact_photo_menu($a, &$args) {
+function retriever_contact_photo_menu(App &$a, array &$args) {
 	if (!$args) {
 		return;
 	}
@@ -984,7 +990,7 @@ function retriever_contact_photo_menu($a, &$args) {
  * @param App $a The App object (by ref)
  * @param array $item New item, which has not yet been inserted into database (by ref)
  */
-function retriever_post_remote_hook(&$a, &$item) {
+function retriever_post_remote_hook(App &$a, array &$item) {
 	Logger::info('retriever_post_remote_hook: ' . $item['uri'] . ' ' . $item['uid'] . ' ' . $item['contact-id']);
 
 	$retriever_rule = get_retriever_rule($item['contact-id'], $item["uid"], false);
@@ -1011,9 +1017,9 @@ function retriever_post_remote_hook(&$a, &$item) {
  * @param App $a The App object (by ref)
  * @param string $s HTML string to which to append settings content (by ref)
  */
-function retriever_addon_settings(&$a, &$s) {
-	$all_photos = DI::config()->get(local_user(), 'retriever', 'all_photos');
-	$oembed = DI::config()->get(local_user(), 'retriever', 'oembed');
+function retriever_addon_settings(App &$a, string &$s) {
+	$all_photos = DI::config()->get(Session::getLocalUser(), 'retriever', 'all_photos');
+	$oembed = DI::config()->get(Session::getLocalUser(), 'retriever', 'oembed');
 	$template = Renderer::getMarkupTemplate('/settings.tpl', 'addon/retriever/');
 	$config = array('$submit' => DI::l10n()->t('Save Settings'),
 			'$title' => DI::l10n()->t('Retriever Settings'),
@@ -1036,17 +1042,17 @@ function retriever_addon_settings(&$a, &$s) {
  * @param App $a The App object
  * @param array $post Posted content
  */
-function retriever_addon_settings_post($a, $post) {
+function retriever_addon_settings_post(App $a, array $post) {
 	if ($post['retriever_all_photos']) {
-		DI::config()->set(local_user(), 'retriever', 'all_photos', $post['retriever_all_photos']);
+		DI::config()->set(Session::getLocalUser(), 'retriever', 'all_photos', $post['retriever_all_photos']);
 	}
 	else {
-		DI::config()->delete(local_user(), 'retriever', 'all_photos');
+		DI::config()->delete(Session::getLocalUser(), 'retriever', 'all_photos');
 	}
 	if ($post['retriever_oembed']) {
-		DI::config()->set(local_user(), 'retriever', 'oembed', $post['retriever_oembed']);
+		DI::config()->set(Session::getLocalUser(), 'retriever', 'oembed', $post['retriever_oembed']);
 	}
 	else {
-		DI::config()->delete(local_user(), 'retriever', 'oembed');
+		DI::config()->delete(Session::getLocalUser(), 'retriever', 'oembed');
 	}
 }
diff --git a/twitter/twitter.php b/twitter/twitter.php
index c55489a0..59861a35 100644
--- a/twitter/twitter.php
+++ b/twitter/twitter.php
@@ -1363,7 +1363,7 @@ function twitter_fetchtimeline(int $uid): void
 
 			Logger::info('Posting mirror post', ['twitter-id' => $post->id_str, 'uid' => $uid]);
 
-			Post\Delayed::add($mirrorpost['extid'], $mirrorpost, Worker::PRIORITY_MEDIUM, Post\Delayed::PREPARED);
+			Post\Delayed::add($mirrorpost['extid'], $mirrorpost, Worker::PRIORITY_MEDIUM, Post\Delayed::UNPREPARED);
 		}
 	}
 	DI::pConfig()->set($uid, 'twitter', 'lastid', $lastid);