As millennials ‘Venmo’ each other money, banks fight back with their own mobile apps

Apps and online tools could someday overtake cash and checks as the primary way individuals pay each other. (Dreamstime/TNS)

Odds are, you've at least heard of Venmo, but there's also a good chance you haven't used the mobile app or anything else like it to send money to family or friends. 

But that's likely to change over the next few years, as banks, payment companies and even the likes of Google and Facebook push so-called peer-to-peer, or p2p, payment systems – a medium of exchange with revolutionary potential.