This app was mentioned in 4 comments, with an average of 1.25 upvotes
Depends on your phone, if you have an iOS device, get this: https://github.com/limneos/MobileMiner
If you got an android, get this miner:https://play.google.com/store/apps/details?id=com.minergate.miner&hl=en
EDIT: It is NOT profitable to mine from a phone, this is only if you are just doing this for fun or as a hobby.
Ok then. For android there is MinerGate which appears to be a legitimate mining app (unlike others that don't actually mine and give coins for viewing ads): https://play.google.com/store/apps/details?id=com.minergate.miner&hl=en
For iOS there is nothing in the app store, but if you jailbreak your device you can mine with MobileMiner: https://github.com/limneos/MobileMiner
Minergate has mining software avaible at google play :)
https://play.google.com/store/apps/details?id=com.minergate.miner
Using your pc is the best, but for android you could use Minergate to mine Monero (XMR)
edit: link: https://play.google.com/store/apps/details?id=com.minergate.miner