Along with longer battery life, updates to apps and the long awaited ability to work in 2 apps at the same time iOS9 has 2 features to improve security. The first is a longer passcode, up from 4 to 6 digits, and two-factor authentication when you sign in from a new browser or on a new device. iOS9 is currently available to developers; the rest of us should get it in September.
ZDnet have a list of what to check to make sure everything is locked down in iOS9
- use a six-digit passcode
- prevent apps from uploading your data
- enable ‘Find My iPhone/iPad’ in case you lose the device
- require a password with every app purchase
- limit apps from tracking your location in the background
- allow voice and video iMessages to expire over time
- change your default Wi-Fi hotspot password
- enable fingerprint security with Touch ID
- prevent messages and emails from previewing on the lock screen
- limit what you can access without a passcode
- prevent iPhone location-based tracking
- limit advertisers tracking your location
- change your search setting to a do-not-track service
- lower auto-lock to 30 seconds