The only real drawback is that your calendar information is held hostage by the entries on their server rather than your own phone. In the event that their servers crash, you might have a hard time remembering all of the appointments and meetings that you have designated for the time. In addition, there seems to be a queue to download and create an account with this program. Still, as a free app, it is definitely worth a try to see how it compares to the many similar calendar apps that are currently available.
Tempo Smart Calendar App [iTunes]
