I have been working with the Catalyst RC app since it´s early beta stages.
I really made my life alot easier.
The app sends HTTP commands to Catalyst´s build in web-server which has a powerful set of commands.

In the app you can organize your servers by assigning mixes to servers or use mixes as parts of a multiscreen.
Most of the mix setups can be done via the app - it is really practical for keystone or curved screen setups. And even if it only is shifting your mix a little to hit the LED wall pixel accurate.
But there is much more functionality - like send a quick scan files to the servers after uploading new content.
A really nice feature is the Quickpatch routine which does all the layer patching and adressing in Catalyst software for you - saves a lot of time.

If you are a regular Catalyst user then the app will soon pay back in making so much tasks shorter, easier and more comfortable.