MBAppStoreRater is a non-intrusive invitation to rate your app on the App Store.
To see an example, buy Favstand on the App Store (it's great and only $1). Then use it for three days so it prompts you.
NOTE that MBAppStoreRater will work on iPhone, but you will need to do some modifications to the MBNonIntrusiveView code to make it size correctly. I've only tested this code on iPad so far. If you fix it, please fork and submit a pull request!
NOTE this is the second time the rater is shown. The first time the first button text reads "Not Now".
The header describes usage.
I'm Max Howell and I'm a splendid chap.