Hard to recommend, not reliable. – Steady Camera - Video Stabilizer & Slo-Mo Capture Review

This app requires good luck. Too many times, I've gotten the dreaded message saying that my video could not be saved. It's not fair to lose a video you've recorded with no cause or explanation. It should not ever happen. There is no good reason to use this app with the knowledge that it could sabotage you at any time. I have had this app on my last three iPhones and I have this to say: the updates take months to come when a new phone is released (and the app is non functional until then) and there has never been a stable build. Every version has failed to save many of my videos after I push the stop button. It also deletes your whole recording if you sleep your phone before stopping the recording.
Review by Sebastian Muffington on Steady Camera - Video Stabilizer & Slo-Mo Capture.