Hi!
The current version of CalenGoo, 1.5.33, does not work under iOS 8 yet and unfortunately Apple has rejected the version 1.5.34, which would have fixed this issue, today. :-(
I will try to make version 1.5.34 available as soon as possible but Apple's review usually takes about a week. So if you would like to use CalenGoo, please don't install iOS 8 yet.
I will provide further information here:
Additionally I will send another email when the update has been released. I am very sorry that the update wasn't released in time! Apple didn't reject any other updates in the past years. I will try to get the update released as soon as possible!