Google has a tablet app quality checklist recommended for anyone wanting to publish an app for Android tablets in the Play store.
It's no doubt useful for anyone porting their first Android app to run on a tablet (from a phone) but most of the points apply regardless of the OS being used and so could apply to those of you making the transition from Windows Phone to Windows 8.
As an idea of how it is relevant, see this partial* list of section headings:
1. Test for Core App Quality
2. Optimize your layouts for larger screens
3. Take advantage of extra screen area available on tablets
4. Use Icons and other assets that are designed for tablet screens
5. Adjust font sizes and touch targets for tablet screens
7. Offer the app's full feature set to tablet users
8. Don’t require hardware features that might not be available on tablets
* Android specific sections ommitted.