It's an add-on I made for my own site. I make heavy use of the custom profiles to know more about the situation of the customer. This helps others when answering questions.
- Copy the contents of the folder "upload" to your forum
- Go to your xenForo admin control panel > Addons
- Install the new addon
- You can change the settings of this add-on by going to Options > [Mr. Jinx] Profile Fields Popup
- You can modify the style settings by going to Appearance > Style properties > Messages
- Everything is 'phrased', so it should be easy to translate
Profile Fields Popup in action: