A while ago, I asked a question which has been deleted by Community
Some Android apps are in fact ebooks. For example, Learn Lisp
Is it possible to convert android app ebook to pdf or some other document file types? Are there apps to do that?
Andrew T. commented that:
For this particular app: get the APK, open it with zip viewer, and browse the
/assetsfolder; they're in HTML files. I can't answer if there's an automated way to convert it to PDF because the content structure will not be the same for other apps.
Firelord commented that
@AndrewT. good approach. You can add certain tweaks and I think it would make a good answer, well at least for some apps, if not for all. In Android, download busybox, get the APK, and then do
unzip -l APK_PATH | grep -E "FILETYPE$". If there exists a file with your extension, its path in APK would be listed. If the developer went to lengths to change the extension and hide the file, then this would fail.
My questions are:
How can I get the APK file of an app after installing it from Google Play?
Once I find the APK file of an app, can I copy it out of my android phone to my Ubuntu laptop and then extract the hidden document file in the apk file? Or do I have to extract on my android phone?