The company this week said the Gmail for iOS app contained a bug that caused users to see an error message upon launch of the app.
It added it will release a new version soon.
The Gmail app had previously been exclusive to Android-based smartphones.
The iOS version is said to include pull down refresh functionality, email alerts, Autocomplete email addresses, and the ability to navigate the Inbox and read email simultaneously via the iPad.
Apple in Oct. said it sold 4 million iPhone 4S units at launch in the first three days of sale to set a new sales record for the device.