Development of Diabetes Logbook X and Asthma Logbook X has been suspended: while the applications still seem to work in Mac OS X 10.10 there will be no more bug fixes. The development environment (Xcode) has advanced too much since I started these projects on Mac OS X 10.4 and it would require the applications to be started afresh as completely new projects, for which I haven't the time to invest is such a large undertaking. For a replacement Diabetes logbook I recommend looking at DiabetesPal in the Mac App Store. Pascal, the developer, got some ideas from my logbook and so there is a familiar set of reports and features.
The following software is available and all are free, though you may wish to make a donation to my selected charity. Provided as Mac OS X Universal Binary, they support both PowerPC and Intel based Macs.