For an operating system touted as being highly customizable, its a mystery why more manufacturers don't let you program the (physical) Home button. Of course, one tap always takes you to the home screen, but long-pressing and double-tapping are often programmed to take you to places like the multitasker or a voice assistant.
Unless, of course, you use a workaround.
For many phones with a physical Home button, you can customize its shortcuts with the free Home2 Shortcut app.
Step 1. Download Home2 Shortcut from the Google Play store on your Android device. Immediately after it's installed, launch it from the Play download page. It's a pretty bare-bones app, but it does the job.
Step 2. Conveniently enough, the app breaks down the process of programming your Home button into steps. In Step 1, tap "Choose application," then "Installed applications" to choose which application gets launched with a double-tap.
Step 3. In the next step, you have the choice to change the double-tap interval. For example, choosing a slower setting will prompt your phone to react to a double-tap with a longer interval. Right now, keep it at normal.
Step 4. Choose your launcher. If you have a third-party launcher like Apex or Go Launcher installed, select it here. But, if you don't have a launcher, or have no idea what all this gibberish is about, choose the default option.
Step 5. Hit the Home button, and you'll be asked to choose a launcher. Choose Home2 Shortcut then hit "Always."
Now take it for a test-drive! Double-tap the Home button, and you should be taken to your shortcut. If you have a Galaxy S4, and it's still prompting S Voice, go to S Voice > Menu > Settings, and uncheck the second option to launch with the Home button.
If you like the idea of Home button-based shortcuts, check out the other combos Home2 has to offer. For example, you can set shortcuts for Home-Search and Home-back. Likewise, if your phone has a camera button, you can reprogram that, too. Just choose "Other key settings" in Step 1 of the app.