I'm using Windows Phone, so I can't really help you finding such apps, but I thought you can now restrict apps for what they do. For example, I can stop them from using internet and thus blocking the app from synchronizing with some server online.
If you're going to create your own apps you can take a look at Xamarin. It allows you to create cross-platform native apps in C# (which I find allot easier to write in than Java). I believe you can download it as an extension for Visual Studio or you can download their own editor which also runs on Linux and Mac.
If you're going to create your own apps you can take a look at Xamarin. It allows you to create cross-platform native apps in C# (which I find allot easier to write in than Java). I believe you can download it as an extension for Visual Studio or you can download their own editor which also runs on Linux and Mac.