ASHKENAZ  I choose my words carefully in this, my first negative review in years of MacUpdate readership.

The original e-mail receipt (dated November 13, 2003) states that "Once registered, the application will never expire and the MultiSync feature will be unlocked to sync all its items. No upgrade fee will never be asked to you, so any future release can be downloaded and used for free . . . " The no-upgrade-fee-ever policy counterbalanced a relatively high purchase price and seemed a good deal both for the purchaser and the developer.

iSynCal 5.6, however, requires an upgrade fee nearly as high as the original purchase price. While it is not unreasonable to charge for upgrades to support continued development, it *is* unreasonable/dishonest/sleazy to charge after explicitly guaranteeing that there never would be such a charge. E-mail to the developer has been ignored. I'd urge potential purchasers to consider the character of the developer before throwing good money after the bad.  
(Version 5.6)