I am not thinking that graphics are required.
Almost all choice-based IF would be naturally suited to be adapted to touchscreen. Something like The Bones of Rosalinda would kick ass in touchscreen format.
And some parser IF would be very amenable to translation, I think, particularly works like Art DiBianca’s which have such a limited command set. Touchable words in text blocks, touchable nouns and inventory, very moderate text/color effects to pay a little lip service to being a “video” game. I actually think Counterfeit Monkey could be translated brilliantly, since you could have a representation of the letter remover (like a little wheel with the alphabet) and a place where you dragged a word to be modified. I have no idea how amenable Emily or Art would be to such an experiment, but I think it could be done without sacrificing the text-based nature of the games at all. Just sacrificing the parser.
Edit:
Here’s a 5-minute mock-up of how DiBianca’s The Wand could be adapted in landscape mode. I would hope it would look nicer than this, because the idea would be to jazz up the text-only game with some attractive text placement. Because the only actions you can take in the game are with the wand, it’s a natural choice for adaptation. The wand has 3 color panels, so you get some color in there. There are some areas that are dark, so the screen goes dark there until you find the right spell.
I am only using this game for throwing-around-ideas purposes. Art has no knowledge of this and has not consented to such an experiment.