By now, you must be familiar with the long press action in iOS. Like when you tap and hold on an app icon and they all start to jiggle. When you press harder on the screen (don't worry, you're not going to break anything), you'll engage 3D Touch. You'll know because one, there will be a vibration feedback on the screen. Second, something will happen on screen.
Think of 3D Touch as the right-click for the touchscreen. it reveals hidden functionality and provides shortcuts for doing things. It's been more than a year since the feature was implemented and it's starting to become genuinely useful. iOS's own shortcuts are helpful and some third party apps also integrate the feature quite well. If you have an iPhone 6s, iPhone 6s Plus, iPhone 7 or iPhone 7 Plus, you really should consider using 3D Touch for the things we have listed below. It's sure to make you more efficient.
Just start 3D Touching the app icons on your Home screen for a start. You'll find useful shortcuts in the contextual menus. They're great for jumping to a particular part of an app.
Also, try this. 3D Touch an app, swipe to an option and then release your finger. Boom, you've just activated the option without even lifting your finger.
Some apps will even show the small version of the widget right there.
Here's a snapshot of 3D Touch shortcuts for the stock apps.
Also see: Top 25 iOS 10 Widgets
This works best if you don't have a huge case on your iPhone. At the left edge of the screen, 3D Touch till you get a vibration feedback and swipe in, to the right. This will open the app switcher screen. Press deeper once again and the app switcher view will open directly.
If you swipe in, and keep swiping to the right edge, you'll end up switching to the last used app.
Since iOS 10, notifications are interactive. And some apps that have been updated (like Uber or Messages) will even show a rich preview of the message when you 3D Touch it, either from the Lock screen or when the phone is unlocked.
You'll also find contextual options there. Like the option to Retweet in Twitter or the option to mute a conversation in Messenger.
While we’re talking about notifications, 3D Touch the x icon in the Notification Center and you’ll get an option to clear all notifications in just one tap.
Whenever you come across a link (and this is not limited to Safari), just try to 3D Touch. The link will open in a floating window. You'll be able to preview it right there. If you want to open the page, press deeper again. Or just lift your finger and it will be gone. Apple calls this feature Peek and Pop and once you look beyond the silly name you find out just how useful this is across the OS. In messaging apps you can use this feature to preview conversations.
The last row of 4 buttons in Control Center (Flashlight, Timer, Calculator, and camera) are now 3D Touch enabled. So you can 3D Touch the flashlight to change the intensity, or the Camera icon to quickly take a selfie.
One of my favorite uses of 3D Touch is when the keyboard turns into a trackpad. Once you 3D touch anywhere on the keyboard, the cursor will be activated. Swipe left, right, up or down to move the cursor.
Press again and you'll get to the text selection. Swipe to select the text.
Say you've got a folder with 3 apps and they all have a couple of notifications each. When you 3D Touch the folder, you'll see a list of all the apps that have notifications and the count. Release your finger on an app name and it will launch directly.
When you 3D Touch an app that's downloading, you can quickly pause it or prioritize the download (helpful when App Store decides to update 30 apps at once).
3D Touch a contact name anywhere in the phone app and you'll get a contextual menu will all off their different contact options. So from here you can call them on FaceTime, send them an email or just a plain old SMS. No need to much about in menus.
You can 3D Touch a song, playlist or album to get the contextual menu.
Send Effects: 3D Touch the blue "up" arrow and you'll get the option to send the message using bubble or full screen effects.
Contact picture: When you 3D Touch the contact picture in the messages app you'll get a menu that lists all their contact information so you can quickly call or email them.
A thread: When you 3D Touch a thread from the app's Home screen, you'll get a preview of the conversation. Swipe up and you'll get some quick reply options.
Tweetbot: 3D Touch a tweet in Tweetbot and you'll be able to see the conversation. When you find a reply tweet, this is good way to quickly view the original tweet. The app icon also has options for directly opening new tweet view.
Instagram: Whenever you see a thumbnail image in Instagram, just 3D Touch is to view it in a pop up view.
WhatsApp: WhatsApp's app icon 3D Touch action shows your 4 recent chats and options to start a new chat or to see your starred messages.
Speedtest: Speedtest lets you start a new speed test, right from the 3D Touch action.
Lose It!: The Lose It! apps quick actions let you quickly log your weight, food or scan a barcode.
It's possible that you think 3D Touching takes to much effort or maybe you end up pressing it accidentally. If you go into Settings -> General -> Accessibility -> 3D Touch you can switch the sensitivity to Light or Firm.
3D Touch is starting to show up everywhere now. And it's really helpful to just get in the practice of 3D Touching. So whenever you think like there has to be a faster way to do something, try 3D Touching.