If you have ever been skeptical of any apk files you find to install on your android device, you can use Waydroid, which I have linked above. It is a sandbox for Linux machines, where you can control an Android device and test the functionality of any Android app. You could also install another app called Tracker Control that tell you all the websites an installed app ‘calls home’ to. You can find Tracker Control on the F-Droid Store. It is really eye opening to see all the places seemingly simple apps call out to. A basic app calls out to advertising & fingerprinting sites, as well as google and amazon, and more for whatever reason. If you do decide to install a certain apk, with Tracker Control you can block all that traffic and save battery life too!