Front-ends

Google Front-end Google Front-end startpage (https://www.startpage.com) or Whoogle (https://whoogle.sdf.org/)
Whoogle GitHub repo(https://github.com/benbusby/whoogle-search)


YouTube Front-end Invidious(https://redirect.invidious.io)      GitHub repo(https://github.com/iv-org/invidious)

YouTube Front-end For android(https://f-droid.org/en/packages/org.schabi.newpipe/)
GitHub repo(https://github.com/TeamNewPipe/NewPipe)

YouTube Front-end For desktop(https://freetubeapp.io)
GitHub repo(https://github.com/FreeTubeApp/FreeTube)

Fotoscan(Google)(https://play.google.com/store/apps/details?id=com.ethereal.openscan)
GitHub repo(https://github.com/Ethereal-Developers-Inc/OpenScan)


Instagram Front-end Bibliogram(https://git.sr.ht/~cadence/bibliogram-docs/tree/master/docs/Instances.md)
Repo I think(https://git.sr.ht/~cadence/bibliogram-docs/tree/master/docs/Instances.md)

Instagram Front-end Barinsta(https://f-droid.org/en/packages/me.austinhuang.instagrabber)
GitHub repo(https://github.com/austinhuang0131/barinsta)

Twitter Front-end Nitter(https://github.com/zedeus/nitter/wiki/Instances)  GitHub repo(https://github.com/zedeus/nitter)


Facebook Front-end frost(https://f-droid.org/en/packages/com.pitchedapps.frost)


Reddit Front-end librreddit(https://github.com/spikecodes/libreddit/blob/master/README.md#instances)
GitHub repo (https://github.com/spikecodes/libreddit)

Old layout Reddit Front-end(https://codeberg.org/teddit/teddit#instances)
Repo (https://codeberg.org/teddit/teddit)

Reddit Front-end for android There is many android frontends clients, but I think this is the best(https://f-droid.org/en/packages/ml.docilealligator.infinityforreddit)
GitHub repo(https://github.com/Docile-Alligator/Infinity-For-Reddit)

Twitch android front-end Twire (https://f-droid.org/packages/com.perflyst.twire)
GitHub repo(https://github.com/twireapp/Twire)


And if I find more the post and pastebin  will be updated