Complete multi-user web application tying into fitness tracker (misfit, fitbit, etc) APIs -- 2

This is a from-scratch project. I would like to have built a complete web application, from the ground up. Users would log into the site, and connect their account with their misfit/fitbit/jawbone accounts (whichever they have). They would then also specify their twitter account username (which we would need them to verify with a DM back to a pre-specified twitter account I own), and/or their FB account (which would need to link back to my application). Then, each day, if the user did not hit their fitness goals for the previous day (as reported by their fitness tracker), the app will post on their FB wall and/or twitter, informing them that they did not hit the goal. The user would need to be able to cancel the service at any time via the website. Application should be easy to maintain afterwards. I prefer python, but am fine with whatever language/framework you feel is best. I have API keys for all the relevant third party services.