You might be using the "mobile" version on your phone
The mobile version of the site does not include all the buttons in the top menu:
Fortunately the "full version" of the site is responsive and perfectly usable on a phone and includes several additional options (including the review queues):
To change to the full version you need to scroll all the way ...
The mobile version of the site won't be improved
On the main meta, there was a post by a staff member stating that there are plans to abandon the mobile version of the site in the future:
We are actively working on the responsive design that works on both desktop and mobile, based on screen size. Once that is finished and perfected, mobile web will be ...
The “mobile” version of the website—the blue-and-white version that doesn't have our site theme—is not getting updated. It's deprecated and it's slated for completed removal (staff post here).
This is because the main site itself—the themed version—is now mobile friendly. If it isn't already showing up that way you need to enable this behaviour:
Make sure ...