Seems perfect, I’ll have a look thanks !

EDIT : not so perfect, I can’t check boxes in md files combining plain text and tasks lists ! wtf

1. reverse image search, upload an image, find a matching image online.

For this I use CircleToSearch app, which works great on android !

https://f-droid.org/packages/com.akslabs.circletosearch

4. a link saver like pocket but simpler (mobile version)

Readeck ? But you have to self-host it first.