Anyone know of an app that provides daily check marks?

For iphone, you can use : http://itunes.apple.com/app/dont-break-the-chain/id313567772...

Thanks for the mention Vijay. Just to add, Rootein also sends out reminders via email/Twitter DMs when it finds you slacking :) We have recently launched a Facebook app (http://apps.facebook.com/rootein) for Rootein. You can track your habits/routines from within Facebook. We just won't give you any excuses to slack :)