Scribl is a free and open source educational video making application for Linux. Using Scribl you can make easy animated Handwriting Instructional videos for your video project or tutorial. It is written using Rust and released under open source Apache License 2.0. It comes in three drawing modes draw in super slow motion, Draw in slow motion and Draw in real time.
You can also set fade effect, add and record audio with your video. It also comes with de-noising and speech detection options. You can export your video in mp4 file format.