Glad to see you are another ENTHUSIASTIC user of Certificate.
As Chad pointed out, Certificate is a donation. My contribution is moral support and that don't pay the bills of people who DO write code and add those improvements that all of us appreciate. They do it in their spare time.
Perhaps Certificate should be included as part of the Moodle Core. It has been around a long time, is relatively stable, it's developers recognized the importance of conditional activities way before Lesson or Moodle 2.0, and some of the most important organizations in the world (humor) can not live without it !
Sigh, and this too shall pass. Happy Holidays Chris