@alain0 This app: https://play.google.com/store/apps/details?id=com.ilixa.onelab (also available on Apple)

It describes itself as a photo editor, but it's a lot more than that. I create most of my designs entirely within the app. It's a collection of different effects that change the image eg by distorting it, changing the colours or adding glitches. Different effects can be added one on top of the other to create more complex images. It's really fun to use.