Why are some Power-Ups not shown inside Trello?

[Dan Smith]

I was searching for Trello help today and was surprised to see some 'new' Power-Ups in my search results.

I rushed back to Trello, but the Power-Ups in question weren't shown in the Power-Ups menu.

Are these unofficial Power-Ups which Trello doesn't promote because they're not proven?

Thanks.

[Matthew N]

Hey Dan

Can you name some example power ups that you're seeing on the help document but not in your board?