With iOS 9 in its early stages, it’s inevitable that Apple is working out the kinks of the latest mobile operating system update. With the iOS 9.0.2 version, Apple sets out to squash a number of bugs. Some of the fixes introduced are for iMessage activation issues, screen rotation issues, interrupted iCloud backups, Podcast app improvement, and problems with cellular data settings. The latest update can be downloaded from the General -> Software Update portion in your main settings. Make sure to plug your device into a power source and connect to Wi-Fi when you update.
The upcoming 9.1 update is said to bring new emojis into iOS, including taco and burrito characters, if those are of interest to you.
Source: Mashable