If you wish to turn your Android device into a fully functional computer, you can search among the lot of launcher apps on the Google Play Store. On Android, you can bring the desktop UI.

When you connect the cell phone to a computer via the USB port, the computer detects the phone as being a removable storage device.

It now seems likely that any Surface phone or mini tablet that Microsoft may create will have an ARM chipset and the emulated desktop apps required to turn it into a PC.