MailWrangler is an app which enables a user to add their GMail accounts (standard and Google Apps For Your Domain) which they could load and switch between them quickly. It embedded Webkit in to the app and logged you in to the accounts automagically. Normally to check multiple Gmail accounts in mobile Safari you would have to log in and out of all of the accounts, typing the username and password for each. Using just the Apple Mail application you aren’t able to see threaded views, your google contacts, archive (quickly), star, etc without going through the hassles that are present when using Gmail’s IMAP on the iPhone. » MailWrangler rejected entry to AppStore