Actually, it is a wonderful question and I am sure in future, cell phones will acts as an auto trading agent, currently we are forced to rent ultra expensive servers, whereas cell phones are cheap, dont take big space, less power usage, inbuilt backup for full day, currently capable of running algos and trading apis, and have good network connectivity.
What some broker or technology provider should come out is, create an Android app that will exposes order sending/cancel/netpos apis through
android services then any external app can make request to that. to sum up - whole analysis and coding job happen inside desktop and live trading u handover to cell phones.