Editor's note, May 26, 2017: Due to increased security concerns, CNET no longer recommends installing third-party apps not officially supported by a device's official app store. In this case, we do not recommend installing a third-party APK not officially supported by Google.
The Google Play store is a great resource that can enhance your mobile experience. It gives Android users access to more than one million apps, such as Facebook, Pandora, and Instagram, among thousands of others, but what do you do when Google unexpectedly pulls an app from its marketplace?
Google has removed apps from the Play store for a number of reasons, the most common being that they violate the company's policy. Once an app is removed, however, all hope isn't lost. You may not have been aware that apps no longer available in the Play store can still be installed on your Android device through a process known as "sideloading."
Here's how to do it:
Setting up your device
From your smartphone or tablet running Android 4.0 or higher, go to Settings, scroll down to Security, and select Unknown sources. Selecting this option will allow you to install apps outside of the Google Play store. Depending on your device, you can also choose to be warned before installing harmful apps. This can be enabled by selecting the Verify apps option in the Security settings.
On devices running an earlier version of Android, go to Settings, open the Applications option, select Unknown sources, and click OK on the popup alert.
Downloading an app
The next step will be finding an Android package file, also known as an APK, which is the way Android apps are distributed and installed. This is where some people usually run into trouble. Never, and I mean ever, use sideloading as a way to pirate applications; doing so will likely result in your Android device getting a virus. You should only download APK files from trusted developers and companies.
For example, Grooveshark, a free online music streaming service, previously had an app in the Play store. After a dispute with Google, however,. Grooveshark now offers the app on its Web site for users to sideload.
You can either download the APK file on your mobile device or on your computer, although the latter is a little more difficult. To get started, download an APK file using either Google Chrome or the stock Android browser. Next, go to your app drawer and click Downloads; here you will find the file you just downloaded. Open the file and install the app.
If you downloaded the APK file on your computer, the process is slightly different. You must connect your Android device to the PC and enable USB mass-storage mode. The next step is to drag and drop the file onto your device. Then, using a file manager, such as Astro or ES File Explorer, you can locate the file on your device and install it.
Remember to be careful when downloading apps outside of official Android marketplaces like Google Play and Amazon's Appstore.