As a professional app, engineered for intensive, day-to-day use, the admin panel is not designed to be used on mobile devices - there is just too much information to fit onto the screen for it to be reaslistically usable on mobile devices.
Having said that, there's nothing actually **stopping** you using the admin panel on your phone if you need to get something done in a pinch, and the admin panel actually looks quite good on certain bigger tablets, particularly in landscape mode.
At the end of the day though, you should plan to use the admin panel on a day-to-day basis on a modern, well specified desktop with a large screen.