Hi,
I'm Arno a student and part time iOS and Mac indie developer from Germany.
After creating PiPifier which enables Picture in Picture mode for every video in Safari I was quite annoyed that most video players don't support a control for the playback speed. So I created Speedifier which lets you control the speed for every HTML5 video in Safari.
If you have an HTML5 video playing on any website just press right and select the Speedifier option you want to slow down or speed up the playback speed of the video.
On some popular pages Speedifier even adds a dedicated button to the video player to control the playback speed.
Speedifier is a paid app (1,99$) on the Mac AppStore. After PiPifier being open source and donation based (via IAP) I choose this approach because I want to support it and add many more dedicated Speedifier buttons to players the users often use. I know it's quite unusual for a browser extension but I think it's worth the price for many users
I hope you like the app. If you have any questions feel free to ask
Glimpse 2
Spot
Glimpse 2