Ios 10 is probably the best and the latest version of ios what AppleInc. has been developing since a very long time. For those who are using ios 10, they might have observed that it shows notification preview on the lock screen.
The worst thing about it is that some messaging services like whatsapp allows you to reply directly from the lock screen without unlocking the device. Also if you are looking for Gbwhatsapp v6.30 Apk Download for android