Hi Rich, don't think there are any mobile apps out there.
PC based would be Aikido 3D. you could compress videos or get ebooks?
besides using your smart phone lots of other stuff that you can do. simply by being aware of your surroundings, your body, your breathing.
My own personal training when I'm walking to/ from work I try to be more aware of my center - practice for my ukemi. sometimes simple things like this we take for granted because its normal to us.
my 2 cents