You can install any app you want from an .APK file if you follow these simple steps:
1. On your device, go to Menu > Settings > Security and toggle Unknown Sources to install apps outside of Google Play Store.
2. Download the .APK file from The Apps Depot or other source.
3. Once the download is finished, pull the dropdown menu or go to Downloads and find the .APK file you need and tap to run it. If you haven't completed the step #1 beforehand, you'll get a notification and would have to confirm that you allow installing apps from .APK's.
4. You'll see a screen or two with a full description of what parts of your device the app will get access to. Press Install to proceed.
5. Run the app when the installation process is over.