Upgrade License or Plan
You can upgrade your current license at any time and pay only the difference.
For example, you've bought a Personal plan (1 site - $60) which costs $60. You can upgrade to the Developer plan (5 sites - $150) by paying only $90.
To upgrade plan:
Log in to your account at flying-press.com/account
Click 'View Licenses'
Click 'View Upgrades'
Select the plan you want and click 'Upgrade License'