There are plenty of image editors capable of doing this, but I personally use Snapseed (available on Android and iOS) to edit my smartphone shots on my smartphone.

I don't use Snapseed to alter my images until they're unrecognizable - it's an app to fix little things that a phone camera may not capture well. Snapseed's 12 filters aren't impressive.

Google has just rolled out version 3.0 for the Snapseed app. This is the first big update the app has received in years.