Android - How to remotely log out all web-based Gmail sessions from my Android phone
I have found two ways to access the “Activity on this Account” feature from the builtin Android 4.0 web browser:
Select the “Request desktop site” option in the browser menu, then open https://mail.google.com — this way it will not redirect to the mobile site. Then use the “Details” link at the bottom of the page, as you would do from a computer.
Open the mobile version of Gmail, select the “menu button” at the top line (with three vertical lines) — it will open the list of your tags. At the bottom of this list you will see a line with “Gmail version: Mobile | Mobile (old) | Full”; select the ”Full” link to switch to the full Gmail version (it looks slightly different than what you get with the first way). Again, you should see the “Details” link at the bottom of the page, which leads to the “Activity on this Account” page.