This post introduces a Chrome extension called One Number. It checks Gmail, Google Reader, and Google Voice for new messages. Many similar tools exist in the Chrome Extensions gallery, but I especially like One Number because it combines Gmail, Google Reader, and Google Voice in one place. Unlike Google Mail Checker, which only checks Gmail for new mail, One Number's author, mzzt.net, is verified by Google, so you do not need to worry too much about viruses.

How to Use One Number

Step 1: Go to http://goo.gl/iYcT and click Install to finish the installation.

Step 2: After installing, you also need to log in so that One Number can get the information it needs (whether there are new messages). Click the One Number icon, then click Log in and enter your account and password.

Step 3: After you log in, One Number checks for new messages at regular intervals. You can also click Refresh to have One Number check manually.

Step 4: When a new message arrives, the One Number icon changes from gray to color. Click the button to see which service has new messages. It also shows how many new messages there are.