Tasks can be synced to Google Task, Toodledo, or Informant Sync.

You must first have an active informant sync account setup and have completed a sync to have the option to add google task or toodledo as a sync account.

Go to Settings>Sync, tap the menu bars at the bottom right and add Informant sync account if you haven't already set that up. Login and complete a sync with your Informant Sync account login credentials.   When you see your last sync date update to today and you have a current expiration date you can add google task or toodledo as a sync account to informant if you choose.

Then when you create a new task in Informant, look at the top of the task entry to see where it's assigned to sync to.  Tap this to change it to your Google task. Toodledo, or Informant Sync account.

On your other device(s) make sure you have setup the same service(s) to allow the data to sync to that device.