The same :(

I have the same problem - during one week synk worked but now its dont work. I bought Pro version.

@ola @kayama @Laimonas Thank you very much for your feedback!

We've just tested the feature of linking to Google Cal, it works. So,

1. Please check if you have set as follow:

Please go to the Settings page on web version: https://i.doit.im/home/#/settings/account , click two buttons:
1) Click “Link to Google Cal", which is used to sync tasks in Doit.im to Google Cal;
But we've found that sometimes, there is a warning shown when we click "Link to Google Cal" on Settings page of web version, then please click this button again so that it will work.

2) Click “Modify the reverse-synced calendar lists”, and choose a calendar of Google Cal, which you may use to sync tasks from Google Cal to Doit.im.

Having finished the above settings, you may see the two sides can sync each other’s tasks.

2. If you want to see the latest data of Google Cal in Doit.im, just click “Sync GCal”. It’s because there are quotas for Google’s sync, that is, it is unable to transmit data automatically to other apps from time to time.

If you still can't see the GCal tasks in Doit.im, please manually refresh your web version.

If check the above, and please tell us if still any problems.
Have a nice day!

And for the iPhone version, I've checked and found that you may see the events in in Doit.im that created in GCal, but you have to tap "Sync GCal" in Settings of Doit.im of iPhone version. And if you still don't see the item, please tap 'Sync' manually since there is sometimes sync delay.

If still any problems, please feel free to contact us.
Nice day!