Useful Drupal modules

Click on the module name for notes, comments, patches.
Recommendations (for and against) are my personal opinion only and may be out of date. Feel free to email with corrections/suggestions.

Why haven't you mentioned Drupal 9? I will be adding this, but as of August 2021, this site you are reading is the only Drupal site of mine I've been able to upgrade to D9, so although you can check D9 compatibility status of all modules (use upgrade_status, it's superb) I can't speak from personal experience about any of them.

(1 modules in list)
Module name or machine name
Any text in the notes
Name D8 Personally Tested Last Updated
Flippy (flippy) 2017-02-06

d.o. page

Add Next/previous links to node view for specific content types - e.g. image gallery.  Powerful - supports: next/last, random link, you can specify exact text used etc.  Currently a dev version in D8.

Setup: activate for a content type in the 'Edit' tab (NOT manage display). Once Flippy is active, Manage Display tab will have a pager field so you can reposition the links relative to other fields on the page (e.g. above or below image).