What Changed and Why
When using the iOS 9 you can simply unlock your phone if you are using the fingerprint recognition feature by pressing the home button. This would wake the device and unlock it.
iOS 10 has seen a major makeover and the most apparent change is the death of the iconic slide to unlock feature. On prior versions of iOS going all the back to the early days (long before finger print recognition) you swiped left to unlock your phone (and put in a passcode if you used one). Even when Touch ID was introduced, the swipe-to-unlock feature remained.
In iOS 10, however, if you swipe left you don’t unlock the phone. Instead, swiping will pull up the lock screen widget panel. In addition, the Touch ID unlock flow was tweaked slightly so that pressing on the home button still activates the screen and unlocks the device, but it doesn’t return you to where you left off (e.g. the home screen page you were on or the app you were using). Instead the device unlocks and sits on the lock screen. If you want to return to where you were, like in iOS 9, you have to then click one more time.
Although it sounds pointless but Apple has their own stance in this. When iOS device is unlocked the apps on the device have access to encrypted data. If you use the default iOS 10 Touch ID unlock method, this means that when you swipe right to open the camera, the camera isn’t in tourist mode but has full access to your photo library. It also paves the way for Apple to allow other apps to appear on the lock screen system and access encrypted data.
Change the iOS 10 Touch ID Behavior back to iOS 9’s
Changing the behavior of the Touch ID unlock is trivial if you know where to look. To change the functionality back to the iOS 9 style you’re familiar with, simply launch the Settings app.
Now go on and tap “General”.
Now scroll down and select “Accessibility”.
Now scroll down again and look for the Home Button entry and select it.
In the Home Button menu you’ll find an entry, turned off by default in iOS 10, and labeled “Rest Finger to Unlock”. Toggle it on, as seen below.
You can now press the Home button and, with a single press, both awake and unlock your iOS device.