Every time Garmin GPS update are notified on my Garmin unit every 2 to 3 months. When Google releases a new version, my phone's OS is automatically upgraded. It is dependent on how frequently and where you visit.
Step 1: Connect your device to your computer. Before beginning the update, connect your Garmin GPS device to a computer.
Step 2: Install Garmin Express.
Step 3: Access or purchase updates.
Step 4: Disconnect your device.
Hope this helps.