I use Snapseed on Android. It's a practical app with many photo editing tools
I like how I can edit my photos here,
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
VSCO - VSCO® is an art and technology company empowering people everywhere to create, discover, and connect. CompanyVSCO® is a trendsetting art and technology company that .
Darktable - darktable is an open source photography workflow application and raw developer.
PicsArt - Explore 100,000,000+ awesome images and photos on the web
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.