Используйте приложение APKPure
Историческую версию Short Video Converter можно получить на Android
Converter any video format to mp4!
You can convert your short video by this app, in the main page,
click the convert bottom to select which video you want to convert, and then you just wait. In the converting, you can not
convert again. The text on the top of convert button, will be refreshed in seconds, and when convert finished, the text will be
writed by the out file path. You can find the converted video in
the path.
At last, your video should be not large, conversion requires a lot of memory.