I wanted to make a family of videos likeand I was wondering if there were any easy plugins/scripts to be able to create and increment the counter while watching a video. I envision something that operates like a little html/java script that increments on a keystroke as you run through the video, that you can later style something like CSS. I obviously am not saying it has to be exactly like this, but in essence I want to know if there are any bits bits of software like that. If not I might just try making it.
In that case Adobe After Effects can do this easily, which probably also produced the effect in the video. It's actually the only software where I know you can do this without too much manual labor. Other products usually only offer a timer effect which would be tedious to use for these kind of things.
Be advised that this won't be a task that you can finish in 1-2 days if you haven't worked with After Effects yet. Especially the scripting part. Do it manually first and then look how you can automate it via a script.