APK files are popularly known as Android Application Package which is actually a package file format which can be used to install application software in android smartphones. The files which are downloaded in the android phones are always saved with an extension “.apk”. A program for an android is compiled when an APK file is created. APK file contains all the program resources, certificates, code and also its manifest. There can be lots of situations where you can these files from your Android smartphones.  There can be lots of reasons behind the loss of .apk files. Below mentioned are some of the most common scenarios that can lead to loss or unintentionally deletion of android application package files: