Implement deshaking or stabilization video filter
I am looking for this effect since Youtube has been removed in August the feature to "Stabilize" the video. It is also called "Deshaking".
VirtualDub has this integrated also if you want check, a nice video is: https://www.youtube.com/watch?v=og4bVk6V7X8
I think that a lot free open source youtubers will need this and pitivi will gain a lot popularity for this if it gets implemented.
See transcode too as tool (open source): http://public.hronopik.de/vid.stab/features.php?lang=en
Also see competency like "Filmora" implementing this feature already: https://filmora.wondershare.com/video-editing-tips/video-stabilization-solution.html