We regret to inform that Appigo Sync and the standalone Todo iOS app is being deprecated and will not support Outlook 2016 or higher.
The description of this application on the Appigo website and the Apple App store both say that this stand-alone app will sync with Outlook.
If this is not longer the case these should be changed and it should be clearly noted this is not now available.
We're sorry for the troubles, regrettably the standalone Todo app is no longer being supported therefore while it will continue to work with older versions of Outlook (2013 and older) the app is not compatible with Outlook 2016. Please reach out to Apple via the link on your receipt to enquiry about being refunded.