The First Digital Currency You Can Mine On Your Phone Start earning cryptocurrency today with our free, energy-light mobile app. Try it, it's free and you can earn coins. Mining with your phone! Pi 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 and use my username (promotor) as your invitation code. Pi makes crypto mining easy. Breakthrough tech allows you to mine on your phone without draining your battery.