I'll be honest, I haven't actually tried out the Snapseed app yet but it comes highly recommended by a trusted source. Photo manipulation apps can be a tricky source of ire for a lot of people but having used the likes of Mill Colour, Hipstamatic, Pano and (lately) Magic Hour, I know that it can be done well. I am a bit hesitant to spend $5 on an app that, likely, does the same thing as other free apps but it's entirely plausible that it does it better - and that's worth a lot.