I just did a little test on the iPhone version of ASP, which I assume works the same on iPad- I was able to import a font by putting down some text, selecting it, opening the tool options window (three little dots under the brush size/opacity sliders), and then clicking the font name to enter the font selection list, and then clicking what looks like an export button (little box with a arrow pointing up). It’s actually an import button! I found a font file and it appeared at the top of the list. Hope that works for you.
