It's a bank startup which doesn't have physical locations. They're partnered with Bancorp, so your account is backed by FDIC, and they have a large number of ATMs. You can read more here https://www.simple.com/
I could say horrible things about them. Like when I was in school and my student loan disbursement came on a Bancorp debit card, and they charged me money to withdraw funds. Yup, if I wanted to buy books with my student loan disbursement, I got charged bank fees on money I got from a loan and paid interest on, and had absolutely no choice in the matter.
Yeah it was my school's decision, but that doesn't excuse Bancorp from offering a product that is designed specifically to cheat people out of their money.
As I understand it, Bancorp is just contracted by Simple to hold the funds and interface with the banking system. All of the policies, support and user-facing parts are handled by Simple itself.
Actually it's the other way around. Simple is the public facing interface that is beholden to all of the policies and inconveniences of Bancorp. Don't get me wrong I love the service but full disclosure it's Bancorp with makeup. Now I have had instances where they where Bancorp was closed for a holiday and my direct deposit didn't get processed and I had bills that were going to hit that I needed access to my funds and they were very helpful and happy to do a temporary credit to my account to make sure that I got what I needed.
I switched to Ally for checking & savings a year ago, and I absolutely love it. Best mobile & web UX I've seen from a bank, best interest rates out there, ATM fee reimbursements, and easy mobile check deposit.
This, plus a pretty unique system for allocating cash around. Perhaps it's psychological, but I've been with them for about 3 months and have started burrowing out of a years-long financial hole in pretty short order.
Basically, imagine the envelope budgeting system as an actual part of your account, combined with a daily savings option. Assuming that you enter your bills in correctly (and it's, erm.. dead simple), you know immediately how much cash you have is safe to spend.
Great CS as well. Actual humans who speak English and who can solve your problems.
There's got to be more to it than that, right? There are lots of internet-only banks. I use Ally.
http://www.gobankingrates.com/banking/10-online-banks-2015/