Popular e-mail app Mailbox has been redesigned specifically with the iPad in mind following a successful run as a general iOS 6 app. Version 1.3, which is available immediately without the wait, also includes some general bug fixes although it is still only available to Gmail users.

Mailbox CEO Gentry Underwood said the initial version of the app did work on the iPad but the layout was designed with smaller devices in mind. The updated app takes the iPad's larger screen size into consideration while still keeping the simplicity of Mailbox in mind. Many of the changes are described as small but practical.

Mailbox first launched in the App Store back in early February but due to overwhelming demand, the company decided to fill reservations on a first come, first serve basis. Sign-ups for the app began in mid-January and by the time the app launched, there were already 300,000 users in line.

A month later it was revealed that Dropbox acquired the small startup for between $50 and $100 million. The 14-member Mailbox team joined the Dropbox team and since then, the app has amassed more than 1 million users that send over 100 million messages each day.

Mailbox is still working on versions of the e-mail client for Android and desktop computers although no timeline for release has been given. In the interim, however, the company is keeping a close eye on how users interact with the iPad version to determine what features may be added to future revisions.