Well, first of all, we use it on our very own website to manage its content in the back-office.
The transition from our previous home-made interface took about 1½ hour for the HTML part. The JavaScript needed some more adjustments as the markup it relied on had changed.
As we also develop projects for clients, Adm'in.2 comes in pretty handy when we need to setup a back-office.
This mobile app (Android & iOS) uses an API with a back-office based on Adm'in.2 to make it beautiful and responsive: people in charge of the project can access the BO and change the contents of the app with their favorite browser without the need to develop or maintain a CSS stylesheet (except for 12 lines specific to the project).
If you use it too, please tell us! We'd love to see what you've done with it!
Simply give us the URL of your website (you don't have to give us any access to the admin section) and a few screenshots (especially if you customized the theme) so that we can keep a record of what can be done with it.