I did not test it. If you’re interested, why not trying out and share your experience?
Gimp was chosen for 2 reasons. 1) I used it for a decade on desktop and love it (with ups and downs) and 2) I wanted to test how a real desktop app is doing on Librem 5 (including calculation power which is good enough!).
There is no real need for such apps in my use-cases, since I’m doing things more efficient on tower.
MyPaint partially works using Mobile Settings. The top toolbar responds to input, but the one below that with icons does not. The OSK works fine. Drawing does not seem to work.
Otherwise the right window will cover the whole screen and you don’t see your edits before pushing the OK-button. All done via touch screen, but it’s also bit imprecise (especially the select tool).
EDIT: BTW, that last pic is from desktop, just because I wanted to capture the entire page in the screenshot. It’s the same on L5, but I would have had to shrink the scale down to fit it all in one shot.
Here’s one I know people will love: Butler, a HomeAssistant GUI. Scales perfectly from what I’ve seen to mobile, developer has not yet marked it as mobile friendly, but they clearly developed it to work well with mobile Linux.
QModMaster on the left is a Modbus protocol test tool. PicPlanner on the right can be used to plan that perfect picture but I tend to use it for knowing the moon and sun positions, max angle expected and when, etc.
QModMaster I did have to shorten a couple of labels and reduce the forms max allowed size but that was about it. Isn’t it awesome to have access to the source code.