A portable version of BL is possible.

Now squeeze that onto this:

(picture is supposed to be actual size lol)
iPad is a whole different story. Eventually, when these devices have more RAM (I believe 4th Gen iPod touch/iPhone has about 500MB of RAM, basically the same as the computer I use nowadays since my hard drive crashed...) this may be possible, but the only probably device that could handle this as well as be usable is the iPad.
Although the iPad version is plausible, it's not probable. Much easier to just stick with more powerful (at least in this case) laptops and desktops.