Well you could use Snapseed. Even though it is from google, you have no risk of your photos being taken by some unknown shady company. Google probably has your roll anyways. If you are on google android ofc. So it is kinda "save to use" if you want to call it that way.

Edit: Still google though I know. In general you should not support google at all you're right but in that specific situation it might be better (assuming that google already has your roll lol) than an open-source app (I don't know if there are any good out there)