I use the calendar now for a little over half a year. First on my Kindle Fire HD, and later also on my Smartphone. The calendar can be operated easily and intuitively. Well, I think that one can also create recurring appointments. It can be used as a local calendar or for synchronization with other calendars (Google ...). In the Pro version, it is possible to copy the data over a backup of one device to the other, what I did after buying my smartphone even so, since I did not use the synchronization. For the synchronization with Google, I then simply copied my local calendar on exactly this backup function in the yet empty Google Calendar in business later Calendar. The synchronization between smartphone and tablet works perfectly so far. The app also cooperates well with other apps. So I have recently taken over all these appointments in the Business Calendar on a Feiertage- and Holiday App.