Where did those first tasks come from?

Hi Steven.

When you first launch GeeTasks you have to connect it to your Google account before the app can be used.
Once the google account is connected, the tasks from Google Tasks are downloaded, and from that point on are kept in sync - changes made in GeeTasks get synced to Google Tasks and vice versa. In fact that's the entire purpose of GeeTasks.

Does it make sense?

Google Tasks on iOS