Frotz isn’t exactly an ereader app–so I can’t compare it to the other apps–as it’s a program that runs interactive fiction (IF) rather than ebooks. IF is a niche within a niche, sort of a cross between Choose Your Own Adventure books and old point and click computer games like Monkey Island, King’s Quest, and Maniac Mansion; akin to the hypertext literature championed by Robert Coover. It’s a form of entertainment that’s been around since the 1970s, when computers didn’t have graphics, and it’s nice to see that it still hold up so well on an iPhone app almost 40 years since the first (called Colossal Cave Adventure).
For such an old medium, there are a large amount of IF pieces still being programmed, and many are creative and well written. The genre is kept alive by a vibrant fan community, and you can find most any available IFs through their Interactive Fiction DataBase. Some of the writing reads a bit fan-fictional in quality, but much of it is surprisingly good. Awesomely, Frotz comes with 25 of the most popular IF titles preloaded. Plus, it can connect automatically and easily to the IFDB, allowing you to download and read/play on your device virtually ever IF title available
Releasing an iPhone optimized version of their expansive if 
Google has optimized (
