Five and a half years ago, I wrote about how Crosswords were the prototypical mobile killer app. It was one of my first and probably best blog posts about mobile and a bit wordy, but in general it boiled down to crossword puzzles being familiar and updated daily with new content, thus a great mobile app. (I also suggested making money from advertising, explaining that Internet advertising wasn't dead, which in the days before AdSense, I thought was quite a statement).
Turns out my thoughts on crosswords back then are still quite accurate. Eliza Block is making up to $2000 a day from her 2Across iPhone crossword app, which since she did the app in her spare time, is quite the nice windfall. The difference between then and now is she is making her money via AppStore sales rather than in-game advertising, which works fine since all the puzzle content is out there available for free download. It still makes me wonder what other types of apps are out there that have daily updated content which you can make a game around? Sudoku is an similar - but the puzzles aren't really a daily or topical thing since you can have a computer generate millions instantly. Crossword puzzles - especially something like the New York Times - are something that is culturally ingrained and an obsession for many.
iPhone DevCamp is going on today up in San Francisco, and it looks like there's plenty of room... too bad I don't have a Mac nor am I an Objective C developer either, otherwise I might go up and develop some app I wrote about half a decade ago and make some coin. Yeah... right.