I don't understand what is this thing for and there's no clear explanation anywhere on the homepage. Can someone enlighten me please? Is it another PayPal killer or something?
Someone writes you a check for your birthday, you don't have to drive to bank (or mail) to deposit. Simply take photo of front/back and send it via app and money is deposited into your account.
Simple is an online-only bank (in essence) that's trying to do a lot of things "right." There's more to it (they call themselves a "bank replacement"), but that's the basic idea.