Done installing GrapheneOS. What apps are must-haves?

Tip: this document will later grow into a setup and configuration guide.

The first thing I install is F-Droid.  Most of the rest of the apps are installed using it.

After installing F-Droid, remember to remove the "install software" permission from the app you used to install F-Droid.

Then I lead with:

• Binary Eye: scans QR codes.
• Syncthing-Fork: I use it, among other things, to synchronize app backups (like Signal's) from my file server back to my phone.  I like the Syncthing-Fork fork better than the main release because the UI is more useful and it seems sync is more reliable.
• Aurora Store: useful to install Signal.
• Signal: only available through the Aurora Store.  With the backup on my phone ready to be restored — thanks to Syncthing — I can restore my years-long Signal history.
• Etar: because I need a calendar.
• Vanilla Music: because I need music.  The music comes from my file server into the phone via Syncthing as well.
• NewPipe: to use YouTube and other tube sites.  Add this app's own F-Droid repository to F-Droid — they release fixes much faster on that repository.
• Simpletask: the best GTD to-do list app I have used so far.  I sync its todo.txt file using Syncthing.
• VLC: who doesn't want to watch all kinds of videos?
• Element: so I can use the Matrix chat network where many of my friends and groups are.
• Markor: very versatile and fast "rich" text, to-do list, and wiki editor for your phone.  Its data can be synced using Syncthing.
• Infinity: great-looking Reddit client.
• Firefox Focus: excellent to browse one-off sites without worry that you'll be tracked — sessions are erased after browsing, and it has evolving fingerprint resistance.  I use the FFUpdater app from F-Droid to install it and keep it up-to-date.

Other apps you may be interested in:

• Telegram: available in the F-Droid store — and without the censorship imposed by the Google Play Store monopoly.
• WhatsApp: available through Aurora Store.