Apple introduced the Taptic Engine with the iPhone 6s, where it replaced the old vibration motor and was also used to provide haptic feedback for when you activated 3D Touch. This year with the iPhone 7, Apple has improved the Taptic Engine and it plays a critical role in simulating the press of the Home button, which is no longer a physical button. But the Taptic Engine in the iPhone 7 goes even further with the introduction of System Haptics, where a number of UI elements in iOS will now also provide tactile haptic feedback when you activate them.
I have had my iPhone 7 for nearly a week now, and these new System Haptics have been a great delight to discover, and use. These System Haptics are mostly subtle and feel very natural, so you may not have even noticed them. Below I've compiled a list of all the places in iOS that I've noticed them appear.
When you slide open Control Center, you get a subtle tap as it reaches the end of the slide.
When you slide open Notification Center, you get a subtle tap as it reaches the bottom of the screen.
Pinch to Zoom
When you use pinch to zoom, you will get a subtle tap as you reach the maximum and minimum threshold of zooming.
Any slider, whether it is a volume slider or brightness slider will also provide a subtle tap as you reach the maximum or minimum value.
Toggling a switch on or off will trigger a subtle tap.
Pull Open Spotlight
If you're in an app and slowly slide down from the top of the screen to activate Spotlight, you will get a solid tap.
Number and Date Pickers
When you spin the number or date pickers on an iPhone 7, you will get the subtle but noticeable sensation of your iPhone "clicking" as you spin past each option. It feels almost like you're spinning a padlock. This is easily one of the most delightful little touches in iOS and the iPhone 7.
Table View Section Index
Similar to the number and date pickers, if you run your finger over a table view section index (aka the little alphabet to the right of your screen in the Contacts app which allows you to jump directly to any letter), you will also get a delightful Taptic feedback.
Pull to Refresh
If you're in Mail or any other app that uses the iOS pull to refresh UI, you will get a subtle tap when you have pulled down far enough to trigger the refresh.
Activating the Home Screen Icon Adjustment
When you tap and hold on an icon on the Home screen so as to move the icon, you will now also get a subtle tap in addition to all the icons wiggling.
Rearrange iMessage Apps
Just like rearranging Home screen icons, you also get a tap when you adjust iMessage apps. But you also get another tap whenever you move an iMessage app over or past another icon. It's a great additional piece of feedback that I hope is also added to the Home screen icon movement gesture.
The keyboard doesn't provide Taptic feedback for every key press (though I would like to have the option to at least try that). What it does do though is provide some Taptic feedback when you tap and hold on a particular key to bring up the alternative options, such as the various accents on the letter E or the different currency symbols when you press the $ key. The feedback occurs not just when activating the alternatives, but also as you slide your finger over each alternative option.
Swipe Table View Cell
If you swipe on an email to archive or mark it as read you'll get a subtle tap. You'll also get this in News or for any other table view cell that supports this kind of swipe to trigger an action. (via @rennarda and @TweetByDavid)
Reorder a Table
If you reorder a table, such as the order of your widgets, you'll get a subtle bump as you move one table entry over and past other entries in the table. (via @rennarda)
Swipe Across 3D Touch Shortcuts
When you activate the 3D Touch Shortcuts on an app icon and then swipe your finger over the available options you'll get a subtle bump as you pass over each option. (via @TweetByDavid)
Editing Photos: Revert to Original Level
If you edit a Photo's color or other attribute which involves a slider, and then decide to revert it back to the original level, you'll get a subtle tap as you reach the original level. (via @TweetByDavid)
Rotate Ruler in Notes
When you use the ruler in Notes, you'll get subtle taps for every 45 degrees that you rotate the ruler. (via @TweetByDavid)
Added Thursday, 29 September 2016:
When you rotate the Compass app past each 30° notch you'll get a subtle tap, ditto for when you reach 0° using the level in the Compass app. (via @TweetByDavid and a bunch of others)
iMessage Screen Effects
Lots of people sent this one in, and it is truly fantastic. They all feature some kind of haptic effect, but easily the best ones are the lasers and the fireworks.
Selecting Burst Photos
When you use the burst mode on the camera, and then go to choose which ones to save, you'll get a subtle tap every time you pass one of the "recommended" photos. (via @100fullduplex)
Video Scrubbing Speed
When you are scrubbing through a video and drag you finger up or down to adjust the speed of scrubbing (e.g. from Hi-Speed Scrubbing to Fine Scrubbing) you'll get a subtle tap. (via @extremeboredom)
Shake to Undo
If you shake your phone to undo, you'll get two subtle taps to indicate that you've triggered the feature. (via @botkillr)
Disable System Haptics
If you're not a fan of these new System Haptics, you can turn them off. Go to Settings > Sounds & Haptics > (swipe to the bottom) and toggle the Systems Haptics button.
The new Taptic Engine is also available to developers, who are also able to implement Haptic feedback in their own apps.
Haptic feedback provides a tactile response, such as a tap, that draws attention and reinforces both actions and events. While many system-provided interface elements (for example, pickers, switches, and sliders) automatically provide haptic feedback, you can use feedback generators to add your own feedback to custom views and controls.
Are There Others?
I've been trying a bunch of things across iOS to try and find all of the System Haptics, but I'm sure I've missed a few. If you know of any others please let me know on Twitter @greyham, and I'll update this story.