I just released a beta for the next version of Sly, my open source image editor on Flathub and Google Play.
Please help test it and report any bugs if possible!
New features include multiple image editing with copying and pasting edits and a full-screen image viewer.
Details on how to set up Flathub beta: https://docs.flathub.org/docs/for-users/installation/#flathub-beta-repository
(PS: it will probably take bit for the beta to be published, so if you're reading this right after I posted it, check back a couple hours later.)