The default android app that I'd like to improve upon is the calculator. It leaves much to be desired. Though it does have a few scientific functions, it has only one mode, making it useful for not much more than basic problems.

As seen here in the collage, the Windows App provides extensive options for math. It also provides conversios for anything you could possibly think of. Temperature. Measurements of length and weight between American standard and metric systems; There's even a function that helps to discern how many days have passed between arbitrary dates. For improvement upon the original android app, I'd like to build on it by adding some of these functionalities.

Beyond that I would like to lump in other stock programs in with the calculator app. For this iteration I'd like to go with the calendar, clock, notes and file apps ("file" is the default name for the app that allows the user to view and move the files stored in their phone's memory). All of the afforementioned apps replace things that would be found on an office desk in the years prior to their functionality being reduced to handheld device software. As such, I believe they'd fit well into a catchall "Desktop" app. Go here to see an example of what it'd look like.