"Stay Logged In" checked by default
What it says. Otherwise when someone registers and/or logs in, it's not checked. Eventually it gets annoying to have to log in every time so this checks it for you.
Allows those with permission to do so to change the author of a thread (first post)
Allows those with permission to do so to change the date of any post. Turned off as it is rarely needed but occasionally handy (really handy during the conversion)
Contact Us by Waindigo
Provides selections for who to send a message to via the Contact Us form. Realistically, could ditch this one.
Enable Debug From Admin Home
What it says. Adds a checkbox to the main ACP page for enabling debug mode. Otherwise you have to edit the config.php file to enable it for a specific user. Note that the "enable" box should never be left checked after you are done with debug mode, because this addon puts the entire site in debug mode - for everyone. So they see weird stuff on the forum pages, normally hidden error messages, etc. This was mainly installed so that I could easily bypass Tapatalk's splash page junk after an upgrade. The Addon itself can be left enabled, that alone doesn't put the site into debug mode.
Expiring User Upgrades
Does what XF should do by default, notifies users when an upgrade it going to expire prior to it actually expiring. Quite a few settings in weird places (phrases dictate email content) so this one will have it's own topic.
Adds a link to the thread tools. Probably not used but it's free
Find Unanswered Threads
Adds a link to the forum/thread pages.
Forum Warning Message
Not really used. Could remove. Intention was to notify people going to BST of the rules every now and then. Causes some issues though, dev is gone, not sure it's being maintained.
ACP only addon. Extremely handy. Automatically backs up the database and XF files daily via cron jobs. Files are kept on the non-public side of the server, 7 days of backups are kept. Hope I never have to rely on this addon!
Adds link to forum/thread pages
HX - Lock Thread Reason
Enter a reason for locking a thread.
Was used after settings were changed to automatically resize large uploaded images. Previous images were huge, this is a batch-resizer. Not really needed anymore, prob could remove.
Join User Group
Buggy. Hopefully will be re-written. Deserves own thread
Last Post Avatar
Adds a mini avatar next to the "last post" username in various places.
Adds a red bubble with the number of alerts you have to the favicon on the browser tab in real time. Other options available also.
Silly addon. put / and me in anywhere and it replaces that with your username and italic/bold/colors the sentence.
Mini Avatar with Tags
Adds a mini avatar when someone tags you
ok I'm tired of writing this. Will add to it later