License for Google Pdf Viewer APK

Question

My company sells Zebra Android devices that we install our own app on (the devices are like a phone, but with scanners and more durable hardware). We can order the devices with the GMS or AOSP operating systems. If we order AOSP then there is less setup, but we would have to load a PDF reader on the device. One solution is to side-load Google's PDF Viewer from APKMirror before distributing the devices to clients.

Since APKMirror states that they manually verify each apps signature I am not too worried about security, but I am confused about how this is licensed. I opened "About this Viewer" from within the app and saw a plethora of Open Source licenses, which all say the app is free to use and distribute. However, I thought all apps provided by the Play Store were licensed only to the individual downloading the application. IE - APKMirror would have to violate the license to generate the APK, unless they received an APK directly from Google.

I understand that each app developer is responsible for licensing their application independently. So, in general, is it enough to verify the signature of the APK from APKMirror and read the license agreement within the app itself to verify that the app is ok to redistribute?

Answer 1

If you were making a gaming device and side-loaded Sony apps from APKmirror, how do you think that would turn out? Doing similar with Google apps, for which you don't have written permission to redistribute, could easily turn out the same way. The risk you run is: you will likely get sued (especially if you company/product is successful, or even if your client is successful).

Answer 2

I'm going to try and condense the helpful comments above into a single answer. First of all, permission must be obtained directly from the app developer to legally use/distribute any app from APK Mirror.

APK Mirror protects themselves with the DMCA (https://www.apkmirror.com/dmca-copyright-infringement-notification/). I guess the way it works is that, since they distribute stuff online, their liability is limited by the DMCA so that they need only respond to copyright infringement requests in a prompt manner, and are not held liable if they post an APK that infringes a copyright; provided that the infringement is not obvious to them, and they don't make an effort to hide licensing information.

As a company distributing physical devices, I'm guessing that the DMCA protection would not limit our liability, and there would be no opportunity for us to respond to a cease-and-desist before incurring possible financial consequences.

Therefore, the alternatives are to download stuff from F-Droid (APKs that are explicitly licensed as FOSS), or to contact developers directly and request a license for what can be downloaded from a site like APK Mirror.

However, I am still not sure why mobile apps themselves don't seem to carry licenses within them, like a Windows program would, or what the validity of such a license statement within the app would be.

Please correct/expand any of the points here that are deficient.