Office Design: Office 365 API Tools
This has been out since 8/4/2014, but my friend Jeremy Foster (see https://codefoster.com) pointed it out after a talk he attended. Take a look at the Office 365 API Tools – Preview. This means that you can integrate your Xamarin Android apps with Office 365 APIs, pretty cool, especially considering the issues with getting Windows Phone 8.1 into the marketplace (love the phone, hate the market penetration).
Office apps like Excel are excellent front ends for data collection.
Take a look.