My mini review of the Cinema FV-5 Android application, tested on the OnePlus One phone. The app is able to do all the basic things needed to get a good quality, flat result out of your phone’s camera. It supports: exposure set & lock, WB set & lock, manual focus and lock, low contrast/saturation/sharpness (“flat” colors), 24p support among other frame rates, and up to 40 mbps bitrate. On my phone, it supports up to DCI 4k resolution (the free version of Cinema FV-5 does all the above too, but it goes only up to 720p — which can be enough for most cases). In some phones (particularly if they have Lollipop), the app also supports manual shutter speed and ISO settings. If you couple your phone with a variable ND filter for phones (to control the camera better outdoors, where they tend to overexpose), and a small steadicam, you could have a winner.
It worked fine on my OnePlus One, but on the 1st Gen Moto G with Android 4.4.4 it had problems: no focus, no recording (it only recorded once, and then it refused to do so again). It’s very possible that these problems will go away with a Lollipop upgrade, because Lollipop has a much better camera API.