It appears that Reddit has abandoned their iPhone app.
Apparently, when Reddit has released bugfixes for approval, an approver happened to stumble upon some user-submitted content that was bad, and rejected the app. Multiple times.
So, Reddit gave up on the iPhone app, is making a new web interface, and is open sourcing the app.
This is why the approval process needs some serious work, or better yet, a way to break out of the walled garden.
Source: App Rejections