On the Official Gmail Blog, the mobile team announced three new options for Gmail users: Multiple sign-in, mobile-specific signature, and vacation auto-responder.
As seen in the image below, users accessing their email through the mobile web page can now sign into multiple accounts. Once signed in, simply click on the account switcher near the bottom of the page and select the desired account.
Similar to a desktop email signature, users can now attach a mobile-specific signature that communicates to readers that you were on your mobile device while writing the message.
To activate, simply click on the gear tool under the menu view. From this area, users can easily toggle the on/off switch and update the signature message.
The last update from the mobile team is the vacation auto-responder. Just as the name suggests, this option allows you to turn on, schedule, and create the message for the auto-responder.