Simple started as a great concept, but they kept gutting vital features.
The whole idea for Simple was that it was a bank account that made things simple.
It displayed a "safe to spend" amount that accounted for the checks you wrote via billpay, so you wouldn't have to balance your "checkbook" like in the bad old days.
It allowed for savings plans that would slowly and invisibly skim a certain amount of savings for, say, a vacation. You tell it the amount you want to save, and the date you want it, and it calculates the amount it needs to skim from your paychecks every payday. If you tap into that amount, or it's unable to skim the needed amount one payday, it recalculates the needed amounts so that you'll still have what you need on the date you need it.
It allowed you to have a joint account with any other Simple user, for any reason.
Simple had rates that were better than the big brick and mortar banks (but not as low as credit unions or other online banks).
It was pretty slick. Then they started gutting the features that made it Simple. It started with eliminating BillPay. The entire concept that originally set Simple apart from every other bank was destroyed overnight. No BillPay means that you either have to start using paper checks (and balancing your checkbook), or you have to transfer the money to another bank account or PayPal-type service (why bother to have a Simple account to begin with, then?). Now, there's nothing that sets it apart from even the crappiest of banks.