Google Android encrypted application packages (.asec) are used in Android operating system to protect applications installed on SD card and asec to apk conversion merely represents how these files are handled by the system.
If you transport some application back to the Android phone or tablet, it will be decrypted back to standard APK format (Settings ► Applications ► click on application ► click on Move from SD Card option).Open ASEC file Open APK file
Integrated development environment for Android apps
All the neccesary SDK development tools for making Android app
Set of tools that allows programmers to create applications for Android
Developer tools used to create applications for devices with Google Android OS
SDK Tools for making Android apps
Linux version of the tools for Google Android SDK