Not sure if this is what you're looking for, but from the UX side, Square Cash.
Does one thing, does it well with large responsive colorful UI that still displays everything you need to know. Is minimally invasive (debit card instead of bank account verification). Uses your existing contacts, so everything "just works" by default.
Not looking for anything specifically, I'm just a junior developer and mostly in javascript. I'm just looking for traits, common elements or approaches to beautiful software. So thank you for sharing :D.
Does one thing, does it well with large responsive colorful UI that still displays everything you need to know. Is minimally invasive (debit card instead of bank account verification). Uses your existing contacts, so everything "just works" by default.