A2 App(s) can be put on Freeze or Hold, to stop it from running using Command Line or Web Interface.
A2 Freeze App - Command Line
a2ctl app [AppName] [freeze]
AppName - Existing App Name
freeze - Set app to Freeze
A2 Freeze App - Web Interface
As you login to A2 - Web Interface, you will see Dashboard. Click on "App Action" under "Operations" section:
This will open "App Action" section. Select "Freeze" from Action for given App and Click on "Apply Now" as shown below:
This will ask for confirmation. Click on "OK" as shown below:
Now, the App will be put on Freeze as shown below:
A2 on GitHub
You may also wish to follow the GitHub project if you have a GitHub account. This is also where we keep the issue tracker for sharing bugs and feature ideas.