Hi,
We did mobile application for one of our client and used magento as backend. There are no any issues with it. In general you just need to define interfaces on your device and implement/use existing on magento. For example for list of products you can implement new theme which will return list of products as json instead of html but use the same controller/action. It's just ideas for start if you want to create Omni-Channel User Experiences there are much more work.
Kind Regards,
Art Malkovich - Onilab