This app allows you to convert Google™ Slides easily to a webm video for free.
Simple and easy to use. Convert your Google™ slides presentation to a single video file with this app. It supports multiple options for conversion, including custom video size, duration per a page, fade in/out effect.
Provides connect with Google Drive™.

This app only works locally without going through the server. It allow you to convert instantly, real-time slides to the video file in your browser.
It's absolutely free for those who want to convert slides presentation to webm video.