CodeKit comes with a 10-day free trial. After that period is up, the app enters "read-only" mode. Every feature will still work as before, you just can't edit any settings in the UI.
Meant For Teams
If you own a CodeKit license, but your teammates don't, they can still download the app and use it on your shared project. Once CodeKit enters read-only mode, they'll still be able to compile files, refresh browsers, and even build the project. They'll just have to rely on you to edit settings.
Why?
Read-only mode lets anyone work with a CodeKit project anytime, for free. For example, you can post your project on GitHub and tell people to download CodeKit to build it. They'll always be able to do so without buying a license.
Until now, this has been a major advantage of the free command-line-based task runners. Unfortunately, CodeKit can't be free because it's how I pay my bills. It's my hope that once people use the app, they'll decide it's worth the price.