This guide shows various techniques to install an Android application file (usually known as APK file) on your Android TV (works for Nexus Player, Nvidia Shield TV, Mi Box, Razer Forge TV, Sony Bravia TV, etc).

Install APK files

You've various options when it comes to installing an APK file onto your Android TV. The easiest for less experienced users is to install trough a file manager. For those comfortable with a command line you may prefer to use ADB, a command line tool used for debugging purposes that allows you to install an APK from your computer. Choose one of the two options that you feel more comfortable with, the end result is the same.

Enable Unknown Sources

On your Android TV go to Settings, scroll to the bottom section named Personal, and enter Security & restrictions. In here, make sure the option Unknown sources is set to on (it is off by default). This will allow you to install Android applications (APK files) outside of the Play Store and Shield games store.

Install with a File Manager

For this procedure you'll need to copy your APK file from your computer into a medium that the Android TV can read from. USB pen drives and microSD cards are supported.

On the NVIDIA Shield both FAT32 and NTFS filesystems are supported out-of-the-box (if you don't know what this is, you're probably using one of them without knowing and shouldn't bother with this detail).

Once you've copied the APK file insert the USB or microSD card back onto your Android TV device. It should be mounted automatically by Android, so you shouldn't need to mount it with the help of a third party software. Now open a file-manager, I personally use ES File Explorer, navigate to your external file storage, locate the APK file and open it. This will prompt you with a dialog asking to confirm the permissions for this application, and give you the option to install it.

Install trough ADB

Get ADB on Windows

If you don't already have ADB on your system, you can download it as part of the Android SDK tools. An easier way is to just get ADB and the necessary dependencies.

On Windows you can try this ADB Installer tool which will install both ADB and device drivers. You might need to get extra device drivers for your particular Android TV if those provided by the tool doesn't work.

Get ADB on Ubuntu

If you're running Linux, here's how to install for Ubuntu:

sudo add-apt-repository ppa:phablet-team/tools && sudo apt-get update
sudo apt-get install android-tools-adb

Reboot the computer after.

Get ADB on Arch Linux

On Arch Linux trough AUR:

yaourt -S android-tools android-udev

Then add yourself to the adbusers group:

# gpasswd -a username adbusers

Reboot the computer after.

Using ADB to install APK files

Now that you've ADB, you can simply install the APK file by calling that command line tool like this:

 adb install HumbleBundle-2.2.1.apk 

Note: Don't forget to replace HumbleBundle-2.2.1.apk with the name of your APK file instead.