What are sites that curate a collection of well-done, but simple explainer videos and product demo videos?

You are looking particularly at curated explainer videos only or collections of curated content?

Either, really. My goal is simply to see some great explainer videos.

I built where you can curate the best content around topics. There's interesting content around a lot of important things. Not exclusively explainer videos though.

Also, Kurzgesagt is an awesome explainer video channel.…

I guess Digg is made for that?…

App explainers for mobile or web apps is what I’m looking for. Sorry, I guess I wasn't very clear!