When you build an Afterpattern app, it begins in Test Mode. Test Mode apps are free but they're not suitable for real-world use (e.g. watermarks on documents, all emails are sent to you. Learn more about Test Mode).
To use your app in a real-world context, you must activate it.
To activate your app, you must either purchase an Afterpattern subscription or make your app "open."
If you publish your app to the Afterpattern marketplace (or any publicly accessible marketplace) and you allow others to duplicate it for free, it is an "open app."
Remember, by default, your apps do not store any data. To save data collected in your app you must send it to a database (learn more). When someone duplicates your app, they do not duplicate the database your app may send data to.