Historically, third-party apps like Filmic Pro have turned the iPhone and iPad into world-class cameras. While those apps are still significant, iOS 8 builds some of that add-on functionality into the devices. For a quick rundown, here’s an article by Maya Sugarman of radio station 89.3 KPCC.
You might also wish to check out MMM’s 10-second tip on the Hyperlapse app.