I'll vouche for Simple. Their app and Goals feature are great, but the thing I love is the real time purchase notifications. It's kind of amazing to me that no bank (that I have used yet) have apps with this functionality. It's incredibly comforting to get a notification everytime I buy something. It also helped me identify falsified purchases the moment they happened, which enabled me to put a hold on my card and file a report of the incident within minutes (and all through the phone app!).
I really hate gushing about products and services on public forums, but Simple deserves it.