I was poking around a little bit and noticed that the iPhone app sends passwords across the line in plaintext when logging into vBulletin. The vBulletin forum itself uses clientside javascript to encrypt passwords before it sends your password across the wire, so why doesn't the iPhone app?
Has the Md5 Hash Issue been corrected ? as noted a vb I do not have a phone that your format supports but my users do
Android side is released. vBulletin update will be released in next few days. iPhone side will be included in upcoming release.