These video editing apps are all of high quality and not made for commercial purposes, that's why they won't cost you a penny. This post will cover 3 truly free video editors for iPhone that won't give you a watermark or time limit. Or the 'free' video editing app prompts that you can't edit videos longer than 1 minute on the free trial version.
You may have downloaded a 'free' video editing app on your iPhone and end up with a video with a watermark, which can't be removed unless you pay for its upgraded version.