Well, DJ Almix mentioned the correct answer.. I'll expand some on it.
Dark Basic Proffessional(Our language of choice

Not really, but FPSC uses it) runs off of the Windows Platform only, using Microsoft's DirectX9, even if you were to use a Windows cellphone they do not support DirectX9, especially not the shader functions and other post-processing features.. Not to mention the giant amount of memory FPSC 'abuses', and the fact we more or less need a keyboard and a mouse to get anything done in a shooter.
So unless you manage to find a phone with complete computer specs this is highly unlikely, I mean you'd need ~2gb of space for a simple game..