I was wondering, if I have an app that is available on the Play Store, is it "safe" to provide a direct download of the apk file to someone (either signed with the proper keys, or just debug-version)?
"safe" in the sense of does the marketplace do anything special to the apk to protect the source code, signing keys, etc.?
Reason I ask is a user of my app has said that their Marketplace/Play Store is no longer working and therefore can not upgrade the app - so asked me to email them the apk file.
The app is a free app, so on the surface I can't see any issues - though just wanted to double check.
Although this raises the question - the apks of the apps you download from the marketplace (paid and unpaid) are on your phone. Are these apks (on the phone) somehow unique to the phone/google account? Otherwise, what stops one from buying an app and passing that apk on to others?