Update 1 (08/02/2020 @ 04:27 PM ET): The Tap, Tap app has received two updates since we initially covered it, bringing loads of new features. Scroll to the bottom for more information. The article as published on July 30, 2020, is preserved below.

Following the release of the first Android 11 Developer Preview back in February, we learned that Google was working on a new set of gestures code-named "Columbus." This feature lets you double tap on the back of your Pixel phone to perform actions like launching the Google Assistant, launching the Google Camera app, controlling media playback, and more. In Android 11 Developer Preview 2, Google continued work on these gestures with new actions for taking a screenshot and opening the recent apps overview. However, these gestures were still hidden away from Pixel users, and in subsequent Android 11 Beta releases, were removed entirely. Thankfully, developer Kieron Quinn, also known as Quinny899 on our forums, managed to port this feature so it'll work on basically any Android device.

His new app, called Tap, Tap, brings the double back tap gesture to any ARMv8 device running Android 7.0 Nougat and higher. In the demo video that I embedded above, I double tapped the back of my Pixel 4 to launch the camera app. In this video, developer Kieron Quinn launches the OnePlus Camera app by double tapping the back of his OnePlus 7T Pro. Launching the camera app is not all that Tap, Tap can do, though. Using an Accessibility Service, Tap, Tap can recognize when you tap the back of your Android phone and then perform certain actions, such as simulating a home, recent apps, or back button press.

Tap, Tap uses the same machine learning models that Google trained to recognize double taps on the back of the Pixel 3 XL, Pixel 4, and Pixel 4 XL. That means it'll work best when using either one of these three phones or a device with similar dimensions and build to one of these three. Thus, your mileage may vary in how well Tap, Tap recognizes double taps (especially when you have a thick case on), but I've managed to get this work on the ASUS ROG Phone 3 and Huawei P40 Pro. No special hardware or software version is needed for this app to work since all the app is doing is reading changes in the device's accelerometer and gyroscope sensors. The machine learning models were trained by Google to recognize accelerometer and gyroscope sensor readings that happen when you tap the rear of the device, while high-pass and low-pass filters are used to further refine the sensitivity. Theoretically, then, this feature, or one just like it, will work well on any device that has an ML model trained for it, which is likely how it works on Apple devices running iOS 14 and how it'll work when Xiaomi rolls it out for some devices in MIUI 12.

Tap, Tap - Android 11/iOS 14 Back Tap Gestures for any Android phone!

After installing the app, you'll have to enable the Accessibility Service in settings. Once enabled, you'll have to choose a Device Model in Gesture settings. There are 3 Device Models corresponding to the 3 TensorFlow Lite models that Google trained for the Pixel 3 XL, Pixel 4, and Pixel 4 XL. A sensitivity setting is shown in the app's Gesture settings, but this will be fully implemented in a future release of the app.

Under "Actions", you can choose what happens when you double tap the back of your device. You can have multiple Actions listed here, but Tap, Tap will only prioritize running the topmost Action. If that Action fails to run for whatever reason, the next Action in the list is run. The developer plans to add Gates to Actions so you can block when certain Actions are executed. He also plans to add Tasker integration in a future release.

In the Gates section, you can choose what conditions will stop double tap gestures from executing an Action. For example, if the Gate for "display off" is enabled, then Tap, Tap won't execute an Action when the screen is off. Finally, Feedback settings let you control whether or not your device vibrates and whether or not the device wakes up when an Action is executed.

Tap, Tap is an open source app, so you can follow its development on GitHub. The first alpha release is available for download right now on the XDA forum thread linked below. Try it out and let us know how well it works on your device!

Tap, Tap XDA Forum Thread ||| Source Code on GitHub


Update: Version 0.2 and 0.3 add music controls, Tasker integration, more

Readers have responded overwhelmingly positive to the Tap, Tap app since we covered it a few days ago. As a result, the developer was motivated to add a handful of highly-requested and planned features. Version 0.2 alpha and 0.3 alpha add actions including music controls, volume controls, wake device, shortcuts, direct dialing a contact, and triggering a Tasker event. The last one allows you to basically do anything you want with Tap, Tap since Tasker is an incredibly powerful automation app. Here's a short demo from the developer of Tasker showing off some of the things you can do with it.

Tap, Tap Update Changelogs

Version 0.2 Alpha Changelog:
  • Added Tasker integration for both the Event type as a plugin (thanks joaomgcd) and launching specific tasks (needs permission, the app will walk you through that) - these are under the Advanced category
  • Added music control actions: Play/pause, skip back and forward (thanks timfedo)
  • Improved MD2 style UI (thanks gcantoni)
  • Fixed camera launching capture UI rather than normal UI (you may see a picker now, if you do and don't want that, change the Action to launch app > your favourite camera app)
  • Prevent a non-configurable Gate from being added when it's already in the list
  • Added Gate for when the screen is on
  • Added volume up, down, toggle mute and volume panel Actions
  • Added wake device Action
  • Fixed crash on Android 7 and maybe 8 hopefully

Version 0.3 Alpha changelog:

  • Actually moved Tasker to advanced, and the Task option should now be available. Sorry about that in alpha 0.2.
  • More MD2 style UI changes (thanks Giorgio Cantoni)
  • Switched links to Chrome Custom Tabs, except XDA link when the XDA app is installed (thanks Giorgio Cantoni)
  • Translations for Simplified Chinese (thanks hjthjthjt), Russian (thanks Fedor Shatokhin), Brazilian Portuguese (thanks Rodrigo Souza), Chinese (Taiwan) (thanks Kevin Kung) and Ukrainian (Petro Bilyi)
  • Added an action for launching a "legacy" launcher shortcut, such as Google Maps directions
  • Added the CALL_PHONE permission as a COMPLETELY OPTIONAL permission, purely to support the ability for an absolute mad person to map the gesture to the "Direct Dial" launcher shortcut, which needs that permission. You must grant this manually if you absolutely definitely want to do that, the app will NEVER ask for that permission normally.
You can download Tap, Tap from the XDA Forum Thread linked previously or from the developer's GitHub page.