The developer of this program did a good job laying out the feature set of this calendar. It is highly configurable, customizable, and easy to install. I have really not found anything that can't be done with it. And I have looked at and tried a lot of calendars, both open-source and $$$$, to find the "right" one for this non-profit org. website.
Plans will always be free.
But several users have asked if they could donate, so now you can (via PayPal account or credit card).
Don't donate more than $10. If I were selling Plans, that's how much I would charge.
All donations go into my daughter's college savings account, and are much appreciated.