Thanks guys!
I managed to find an android app called SpinTech that has some, but not all, of the same calculators as iSpin. Still not sure if it will make a decent replacement as the included calculators are things that can be easily calculated by hand and the missing ones are, of course, the ones that I really miss having.
Can someone explain the whole internal memory, internal SD card, external SD card thing? Preferably with small words and using hand puppets? I did see one review for the Galaxy S that said it needed to be jailbroken in order to efficiently load apps with the available memory... or something like that.
Review is here. Anyway, is this true?