applications - How do I save purchased apps as APKs?

I am unable to save APK's that I have purchased (actually paid for) through the Play store. Usually SaveAPK is able to save the APKs that I'm interested it, however this didn't work: it sais Copy failed. I also tried Astro File Manager, but every app that I purchased had a lock symbol on it, and it didn't allow me to back it up.

Next, I tried looking in /data/app, and I couldn't find the APK either. Any ideas where they could be? Maybe it's some sort of copy protection in 4.x+ which I haven't heard of previously.

I am running Cyanogenmod 10.1-20130714-NIGHTLY-i9300

Answer

.apk files are usually installed in /data/app, as you already pointed to. I find my "bought apps" in this place as well; so it might be you've looked for the wrong name: the files usually have the "syntax" -.apk, where is the app's package name as it appears in the URL when looking it app in Google Play via the web browser, and is a digit. I bought e.g. ROM Toolbox, and can find it here as com.jrummy.liberty.toolboxpro-1.apk.

There are several options to get hold of an app's .apk file: