We do not support third-party clients for Android, web, or any other platform.
We’ve become aware of a number of third-party client applications that claim to sync with OmniFocus and our Omni Sync Server. Some of these include Quantus Tasks [previously released under the name AndroidFocus] in the Google Play Store, FocusGTD, and RazorGTD. These apps describe themselves as clients that can connect to an Omni Sync Server account in order to sync with the OmniFocus database that is stored there. To be clear, Quantus Tasks, FocusGTD, and RazorGTD are not Omni Group products, and we are unable to assist customers with using these apps or any other third-party clients.
We believe that you should have control of your own data, and OmniFocus therefore uses an open file format just like the rest of our applications. Customers need to be aware, however, that reverse-engineering sync in the way that Quantus Tasks and FocusGTD appear to have done can make for unpredictable results. That means it’s theoretically possible that using these apps will cause data loss which our Support Humans are not equipped or able to help you recover from. For this reason we can’t recommend using these or any other third-party clients.