I have the premium version, but I still can´t figure out how to sync my iCloud Calendar in the iphone with todoist.
Please follow the instructions described in this article: http://support.apple.com/kb/ht5029 and let me know in case it won't help,
Those instructions are not working.
Which part is not working for you? Are the tasks not showing up? Are you getting an error when you subscribe to your iCal feed?
I've added the Todoist calendar to my mac but it isn't syncing to my iCloud calendar or iPhone. How can I correct this?
Sorry to hear you are having this issue. Please select Todoist from the list of your calendars > click on Get info and make sure that location is set as iCloud (see the screenshot).
Please take a look at this detailed article to make sure you are following that instruction. Let us know if it still doesn't work: https://support.apple.com/en-ca/HT202361