Q: Which of these apps do you own?

A: Both SmartDay for Mac, and SmartDay for iPhone

Thanks!  Since you are syncing between our device apps using mySmartDay, and also between iCal on your devices using iCloud or iTunes, your data will likely be duplicated because of a ‘sync loop.’  Just use the ‘remove suspected duplicates’ feature in Settings of any of our apps, then sync to mySmartDay, then sync the other apps to mySmartDay, and you should be good to go. Duplications should not occur after that.

To set up sync for the first time: In either SmartDay for Mac, or SmartDay for iPhone, just go to Settings and verify your free mySmartDay account.  If you do not already have an account, you can create one from Settings -> Synchronization.Okay, you have both SmartDay for iPhone, and SmartDay for Mac.

Remember: before you sync with iCal for the first time, change any duplicated calendar names in Calendar/Reminders.