One of the cool things about Android is the way you can replace the stock app launcher with any number of third-party alternatives.
During my recent dalliance with the Moto X, for example, I tried a number of them: Espier Launcher 7, Nova Launcher, and, most recently, Aviate. And if you're new to Android yourself, or just looking for a way to give your phone a makeover, launchers can be a lot of fun to experiment with.
Just one problem: It's not always clear how to switch back to the default launcher if you decide you don't like the new one (and elected to make it the new default by selecting "Always" after tapping the Home button).
Fortunately, even if the new launcher lacks a clear exit strategy, you can get the old one back. Here's how. (For purposes of this tutorial, I used a Motorola Moto X running Android 4.4. The process should be very similar on other Android devices, though it could vary in screens and/or nomenclature.)
Step 1: Run the Settings app.
Step 2: Tap Apps, then swipe over to the All heading.
Step 3: Scroll down until you find the name of your current launcher, then tap it.
Step 4: Scroll down to the Clear Defaults button, then tap it.
Step 5: Now, when you tap the Home button, you should see an option to choose the launcher you want (just as you did after installing the new one). Tap Launcher (i.e. Android's native one), then tap Always.
And that's it! Now that you have this little tip in your pocket, feel free to go nuts with other launchers. If they don't work out, it's no problem to revert back to the original, even if it's just temporarily.