Drupal Gardens was an Acquia product much like SquareSpace or Wix. Its base foundation was Drupal, and it later morphed into a project called Acquia Cloud Site Factory.
Acquia hired my then employer Workhabit to build an iOS app for users of Drupal Gardens.
This app would let you login to your site, create and upload content, as well as manage multiple sites. One of the nice features was you could control look at feel of the application via your Drupal site. This documentation post explains how to do that.
Eventually Drupal Gardens was shut down, but this was a fun project that I worked on for about 9 months.