Retro Achievements are live :) Here is a video of them in action There are a few steps to activate them
You'll need to create an account on https://retroachievements.org/

Then you'll need to go to settings

Then Achievements

There you can enable them and enter your username and password. We don't store your password and you will need to enter it on all of your devices.

Then when you open a game that supports achievements you will see a blue banner letting you know that they are active