Can not download an .apk from a URL and install in one process

Using your documentation and online examples we can not properly download an .apk file from our own servers on device, once this file is downloaded we would then want to have the system handle opening and starting the installation process. We were hoping to have this handled all in one simple button click in the settings as a sort of Check for and Apply updates if a newer version of the app is pushed out. We are handling this in the original version of this application via native code for Android and would like to replicate the functionality in this newer HTML 5 / Phonegap build. All attempts thus far have failed. I have also read about ways to make an OTA update part of the iOS build as well with our Apple Enterprise License however we have not attempted this yet as our attempts with Android and the .apk has failed thus far.