You may want to take a look at eliterature.org, for some ideas. I think there is something to be said that visual and interactive novels make up about 70% of game titles released in Japan.

http://en.wikipedia.org/wiki/Visual_novel

An IF novel should do quite well as a mobile App. I've been taking a few stabs in the dark lately, adapting Kafka's "The Metamorphosis" into an IF piece, but haven't had much luck, really.