Search feature in iOS 10 while using any application.
Scroll down from status bar just a little. Once the area is covered only with search bar(as shown in the picture), stop dragging and take your finger off the screen.
Now you should be able to search directly. Isn’t that great?
Here is a video.
Note: This type of search works only when any application in your iPhone is opened. If you are on springboard, you can directly click and drag down to call search feature.