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. Further you can edit, watch, delete and manage them easily using indicator preferences. This utility synchronize tasks easily but first you need to authenticate the application for your account. It has features like manage tasks locally or external, which means you can set options to delete/keep tasks from preferences, also you can manage tasks offline then synchronize later. Additionally you can mark task as completed or delete locally/externally from this utility.
To install Google-Task-Indicator in Ubuntu/Linux Mint open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal: