How to Install Android Studio in Android Phone
Google provides a primary app store for Android, known as Google Play. However, Android isn't like iOS. Google Play isn't the only game in town, and there are other ways to install apps on Android.
Some Android devices — particularly dirt-cheap ones coming direct from manufacturers in China — aren't certified by Google and don't include Google Play. This makes the device much less useful, but you can still install apps on it.
Google Play App
The primary way you'll install apps on Android is by firing up the Play Store app on your phone or tablet. You'll find the Play Store in your app drawer and likely on your default home screen. You can also open it by tapping the shopping bag-like icon at the top-right corner of the app drawer.
Once in the store, browse or search for an app and tap the Install button to install it.
Google Play on the Web
Hunting for apps using a touchscreen keyboard isn't the most convenient way to install apps. To install apps from your computer, visit the Google Play website at play.google.com. You can search and browse for apps on the website.
As long as you're logged in with the same Google account you use for your Android phone or tablet, you can click the install button on the website to remotely install the app on your phone or tablet. If you have multiple Android devices, you can select the one you want the app installed on. Once you've told Google Play to install the app, your phone or tablet will start downloading the app and install it for you.
Sideloading Apps
Android supports sideloading, which allows you to install apps from outside of Google Play. However, this is disabled by default for security reasons. To enable sideloading, open the Settings app on your Android, tap the Security category, and enable the Unknown sources check box.
Note that this can be a security risk, as it allows installation of apps from outside the Play Store, which could potentially contain malware. If you enable this setting, it's your job to install applications responsibly — stay away from pirated games and other apps that may contain Android malware.
After enabling this setting, you can download an Android app in .APK format and install it on your device. For example, you could download the .APK file in your Android's browser and open it from the Downloads app. You could also download the APK file to your computer, copy it over to your Android's file system with a USB cable, use a file manager app to browse to it, and tap the APK file to start installing it.
Sideloading allows you to install a variety of apps that aren't available in the Play Store, such as the XBMC Media Center for Android, various emulators that have been removed from Google Play, and third-party app store apps like the Amazon Appstore for Android and Humble Bundle app.
This option may not be available on some devices if the device's manufacturer or carrier has disabled it. AT&T once did this, but it's become much less common. Most devices should have the Unknown sources checkbox.
Third-Party App Stores
Android allows for third-party app stores. The most well-known and popular one is Amazon's Appstore for Android (currently only available in the US), which gives away a free paid app every day. Amazon's Appstore for Android is also used natively on Amazon's Kindle Fire devices.
The ever-popular Humble Bundle, which sells bundles of indie games for Windows, Mac, and Linux, has also sold bundles of Android games. If you purchased any of the Humble Bundles containing Android games, you could install the Humble Bundle app and use it to manage the installation and updating of your Humble Bundle games.
To use either the Amazon Appstore, Humble Bundle, or other third-party app stores, you'll need to sideload the app store's app.
Some devices may come with their own, integrated third-party app stores. For example, Samsung devices come with the Samsung Apps app, which may contain free versions of some paid apps, but is otherwise fairly uninteresting. Carriers have distributed their own app stores with their Android devices in the past, but this is becoming less common.
Just as you should be extra careful when sideloading apps, you should be extra careful when using third-party app stores. For example, you can probably trust Amazon and the Humble Bundle, but you should beware of many other app stores. For example, an untrustworthy app store distributing pirated apps may be a source of malware. We recommend staying away from those.
Sideloading From Your PC
You can also sideload apps onto your Android device in other ways. For example, if you have an APK file on your computer, you can use the excellent AirDroid app to upload it to your Android device and install it without even connecting your Android device to your computer.
If you're a developer, you can use the adb (Android debug bridge) command to "push" an app to a connected device, installing it from your computer. The appropriate command is as follows, where C:\package.apk is the path to the APK file on your computer:
adb install C:\package.apk
You can also install Android apps on your Windows PC, which opens up a whole new world of touchscreen games and apps on touch-enabled Windows 8 devices.
Image Credit: JD Hancock on Flickr
How to Install Android Studio in Android Phone
Source: https://www.howtogeek.com/161366/5-ways-to-install-android-apps-on-your-phone-or-tablet/