We're demonstrating the process using a Galaxy S6 on Android Lollipop, although it should work on most phones that have a physical home button. By default, a double-tab of the S6 home button takes you to the camera shortcut but, for the purposes of this tutorial, we want to make it launch the Play Store instead. On older Galaxy devices, a single tap of the physical home button will bring you to your home screen, a double-tap launches S Voice, and long-press launch Google Now with a long press.
First, you’ll need the app Home2 Shortcut from the Google Play Store, so download and install it on your device. There are other apps exist that provide the same functionality, but for this example, we’re using Home2 Shortcut.
How to change the home button action
1. When you fire up the Home2 Shortcut app, it will provide a step-by-step walkthrough of how to program your home button for different actions. In this example, we’ll customize what happens with a double-tap.
2.In Home2 Shortcut you'll see a four-step process. It will ask you to choose an application that you want the double tap button combination to launch. Tap Choose application and select the Play Store from the list (or any other app you prefer).
3. Next, choose how long you want the double-press interval to be.
4. When it asks you to choose your Home application, either pick TouchWiz home if that's the only launcher you're using, or your preferred Android launcher, if you have an alternative one installed.
5. Finally, when you press the Home button, you'll see a window pop up asking you which launcher you want to use. Select Home2 Shortcut and tap Always. If you ever want to go back to how it was before, you can clear your app defaults in Settings.
Now when you double tap the home button next you'll be taken to the camera app. Wait, what? Yes, on our Galaxy S6 we were taken to the default camera app shortcut rather than the Play Store, as we'd selected.
There's one more thing you need to go. Go into your camera settings and flip the switch for Quick launch. Now, when you double-press the home button, your Home2 Shortcut action will be the one that takes place.
We actually think that the way the S6 launches the camera from a double-tap of the home button is a really useful feature, so If you have an older Galaxy device, you can use Home2 Shortcut to make the double-press a camera shortcut rather than an S Voice shortcut. As above, you may need to go into your S Voice settings and flip the switch for the S Voice home button shortcut in order to to give Home2 Shortcut priority.