The app, which was first available in private beta, launched as an iPhone app a couple of months ago. Now it has been optimized for the iPad.
The app is designed to make it easy to organize your emails into tasks, trash or to save it for later with a snooze button. The iPad version is designed to be used quickly, as you would just glancing through emails on the go, but it is also designed to use when you have more time, say perhaps if you have a keyboard attached to your iPad.
Mailbox has not indicated if they will release an Android version or if they will offer tools for inbox management that stem beyond Gmail.