If you are designing for mobile cross-platform you might be interested in Maximiliano Firtman’s excellent list of "UI Guidelines for mobile and tablet web app design".
However, my experience of some (not all!) design guidelines is that they are sometimes written by people who know little or nothing about how to implement their guidelines. Blindly creating UI designs from them can sometimes result in very costly implementations. Depending on the application, simpler designs can usually suffice. Alternatively, you can go for all the embelishments if you have the budget and need the best user experience.
Another problem with UI guidelines is that they don’t show how to implement. There always seems to be a disconnect between UI Guidelines and the APIs. It’s not always immediately obvious how to go from one to the other. It would be great if mobile platform providers could provide more guidance in this area.