Here's how you can install the Google Task Indicator in Ubuntu 14.04.
1. Open a terminal window.
2. Type in the following commands then hit Enter after each.
sudo add-apt-repository ppa:atareao/atareao
sudo apt-get update
sudo apt-get install google-tasks-indicator
Google Task Indicator is developed by atareao. There is no official application available to manage your Google tasks but it is fine indicator which can help you to manage your tasks locally or externally. It shows the latest ten tasks with in the indicator.More at Noobs Lab
Additional Ubuntu Resources