No specific info about version 3.5. Please visit the main page of Movavi Video Converter on Software Informer.
Version 188.8.131.52 is also Freeware, allmost it is what i have installed and in about it say it's free.
The latest version 5.0 is a shareware ! ; vesion 1.4 is freeware.
If you look carefully through the page you will see that SI has indicated that the LICENSE type of this program is shareware.
Indeed Its a good software