Streak will update itself automatically in the background, but occasionally you may need to update to the latest version manually.
Chrome
To ensure you're on the latest version of Streak on Chrome:
Navigate to chrome://extensions (you can copy and paste that into your address bar)
Toggle on Developer mode at the top right of the Extensions page
Click on the Update button
Refresh your Gmail page
Note: The version shown in the screenshot above may no longer be accurate if a new version is available.
Safari
To ensure you're on the latest version of Streak on Safari:
Navigate to the Safari menu -> Safari Extensions
Search for "Streak for Safari"
Click on the Update button
If Streak no longer appears in your Gmail after the update, you may need to re-enable the extension:
Navigate to the Safari menu -> Settings
Click on the "Extensions" tab
Make sure Streak is enabled in the settings