You can also use the build-in video converter tools to freely convert video/audio format to another format. It is a non-linear tool, which means you can place video clips in the timeline freely. You can also export your video to IG, FB and YouTube, which is powerful as a free video editor. You can also edit 4K and HD videos. For this point, not every free video editor can do.
FilmoraGo is a video editor app by Wondershare. It's easily one of the best video editor apps. This video editor packs a whallop. You can do the basics like trim and cut, render, and that kind of stuff. It also includes the ability to play in reverse, do square videos (1:1) for Instagram, and 16:9 videos for YouTube specifically. It also has support for things like slow motion, transitions, music, overlays, and more. It's not half bad for what you get. There are in-app purchases that add to the power. However, most of the features are, in fact, free.