Krita if you have an android device with a big screen.
Or Pocket Paint for a phone, but it's not a 'full' alternative IMO.
I found this one recently: https://github.com/burhanrashid52/PhotoEditor
It's on fdroid: https://f-droid.org/en/packages/com.burhanrashid52.photoediting/
For me it has enough features, I can do more complex stuff on my computer
I've been using this for the past decade, haven't needed anything else until I started working with Raw files- for those darktable is all I know but it's also been great.
Someone recommended Image Resizer the other day. There's a little learning curve, but it can do basic edits.
If you have a big enough screen, krita is fully featured.
As far as ads go - you can use adguard's public DNS server without installing anything and it'll block most ads on mobile
To be fair, if your VPN isn't blocking ads, you're missing out.
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
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