19
Foss design app for android?
(feddit.ch)
If it's free and open source and it's also software, it can be discussed here. Subcommunity of Technology.
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
Something like https://f-droid.org/packages/org.catrobat.paintroid/
Its not bad but it seems very basic