Here's how to completely remove Air Flow from your device:
Quit Air Flow
Right-click the Air extension icon from your menu bar and select 'Quit Air'
Delete the folder named for your workspace in Air
Move to bin or trash from your Finder window
Restart Air Flow
The app will alert you that it is unable to find the previously synced folder.
Select 'Stop syncing', which will remove all data from database
Select 'Turn off syncing'
Right click the Air extension icon and select 'Quit Air' once more
Trash the Air app as you would any unwanted Mac app
That’s it! You can now re-install Air Flow here.