Thanks for sharing the LearnVest app. Yes, there are lots of saving/budgeting apps out there. Our idea is focusing on building habits related to personal finance, rather than improving transparency of personal finance. So, rather than trying to get you to check your app to see if you have room left in your coffee shop budget, this app would help you to keep track of behaviors. I keep focusing on "bringing your lunch to work", because it's something that came up during our meetup. Sure, it's a financial decision, but looking at it in the context of a financial decision makes it stressful.
Your insight about using your FitBit for personal accountability, rather than community accountability/support, is interesting as well. Budgeting apps are supposed to keep us personally accountable (I don't think most of us share our Mint login with friends), but a lot of people still struggle to save. Do you think you would track your performance for tiny, daily financial habits? Or is your FitBit effective because it silently tracks what you do without manual data entry?