Pi is the only crypto-currency mine-able using a smart phone at the moment,it mines without draining phone battery and also with out using data.
The pi app is the main base of the currency, with the app you can mine the crypto-currency without hassle and fast too.
Here is a earning proofPi is a new digital currency being developed by a group of Stanford PhDs. For a limited time, you can join the beta to earn Pi and help grow the network. To join Pi, follow this link https://minepi.com/obiaguand use my username (obiagu) as your invitation code.
I will keep giving earning opportunities to you guys just stay tuned,bye.