Gmail for iOS
In the last couple of days I realized that my Gmail did not push into my iPhone as quickly as before. My Samsung chirped faster than the iPhone and after a few hours I realized that there was some problem with the push mechanism for my main Gmail account. An issue as I rely quite a lot on email.
On the very same day, I found out that Gmail app for iOS was released. Was it coincidence. I have since installed the app and it was working great. The emails were punched directly to my iPhone, not through the built-in mail client, but the Gmail app. Labeling was straight forward, but the main issue was, I was not able to configure multiple Gmail account into the app. Luckily, my alternative email account pushed without any issue.