Hyphen also allows you to add your own favorite fonts by dropping them into Hyphen's Documents in iTunes. However, I haven't tried it.
I also just noticed the OP was asking specifically about ereading apps for iPad, so I've corrected my post (#8) above. MapleRead does not have a free version you can try on iPad; only the iPhone version is free (with an in-app purchase to unlock "Pro" features).
Another thing about MapleRead is there are 3 different versions, 2 for iPad and 1 for iPhone. It's not a universal app like Marvin and Hyphen.
That said, I have purchased full/Pro versions of Hyphen, MapleRead and Marvin to support the developers and encourage continued development. A small price to pay, I think, for the enjoyment ereading gives me
