I know that BK team was working on creating an application for Ipad, but I am not sure it is ready yet, I think it is still in Beta testing stages.
In the meantime, we are using tablet PC (netbook, Lenovo).
Of course ( before Ipad application is released) you can use LR/LM on Ipad, if you transfer it from PC nearby via a special transfer program, but you will need to have another computer running in close vicinity to do that.
Here is detailed information on that:
http://forum.brillkids.com/little-reader/little-reader-available-on-the-ipad-today!/
Hope you will have fun!