...
Choose the workspace that you would like to install the app tofor
Once in the chosen workspace, click on Settings
Click on Marketplace under Apps and Features
Click on All categories drop down and choose Code review
Checklist Buddy will show up as an optionFind Pull Request Checklist Buddy for Bitbucket in the list of apps proposed
Click Add and grant access to the app
The app should now be listed under Installed Apps
You're done!