What is a good photo edit app that's free?
Multiple apps have different versions of different effects so you want to get multiple apps to have the best. Color Effects, Transphotos, Aviary, Fotor - PES, Camwow are a few.
The gimp. It's free, open source and cross platform.
I like Snapseed and here is the link: https://play.google.com/store/apps/details?id=com.niksoftware.snapseed&hl=en
Snapseed is my favorite.