This type of app is not particularly monetizable. Most people would use the actual website instead of paying $0.99 cents for an app. Plus, it was a fun project to learn iOS and it costs me very little to host or maintain.
Reddit has a very nice API, one of the killer features is that if you take any reddit page and add ".json" to the address it'll spit out pure json at you.
For example: http://www.reddit.com/r/all becomes: http://www.reddit.com/r/all.json
It works but what it gives you is complete dump of their page, 150K, say.
It would be nice to get just the tops of the comment trees instead. But hey, its there...