Using Google Tasks on Mobile Devices
To use Google Tasks on your phone or tablet, download the free Google Tasks app from Google Play (for Android and Chrome devices) or from the App Store (for Apple devices). From there, using Google Tasks is quite simple:
Enter your Google credentials to log into the Google Tasks app on your mobile device. View the list of existing tasks. To mark a task as complete, tap the circle next to it. That task will then be crossed out and moved to Completed. To add tasks, hit the plus sign at the bottom of the screen. Tap the menu button at the bottom left corner of the screen to create and name additional lists. To rename or delete a list, or to delete all the completed tasks go into the menu button on the right.
Access Google Tasks in Gmail on Your Computer
To enter or view tasks on your computer, visit Gmail, Calendar, or an open document in Docs, Sheets, or Slides. Then:
From the icons along the right side of the screen, select the one with a diagonal line and dot (the bottom icon). A window will slide out from the right that contains your lists. Click the icon next to Add a task to make a menu appear; From here, you can sort, rename, and delete your lists.