This question pertains to the re-link clause of the LGPL specifically on the Play Store.

There’s lots of unclear information about this topic. Assuming there’s an application on the Play Store that has a dynamically linked native library where the lib in question is a seperate *.so file in the APK, is it possible to relink another version of that library you’d need to

1. Access and open the APK file somehow
2. Modify its contents
3. Run the modified APK

I know you can run unsigned APKs by modifying your device settings, but I don’t believe you can access a Play Store APK without root access to your device.

Is root absolutely required to re-link libs in Play Store APKs? If it is, doesn’t that imply that you cannot distribute an APK on the Play Store (or any store that protects user access to its APK files) that dynamically links to an LGPL library on a device that cannot be rooted?

Is this a valid concern (are there any devices that can’t be rooted)?

Assume in this case that the distributors of the LGPL lib clearly require re-linking and don’t provide any flexibility on that point.

edit:
It seems like there’s a workaround that lets you download Google Play applications directly to your computer:
http://codekiem.com/2014/08/07/official-apk-downloader-v2-download-apk-files-from-google-play-store-to-pc/

I feel like this is a temporary fix though and might break at some point in the future. Still this seems to be a way to get an application without rooting your phone at all.