IntegrationPreference Library
· You put IntegrationPreference into your preference XML file and it checks the given intent to it. If it cannot find the application to handle that Intent, it opens Play Store on click to install the required application.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window integrationpreference-support-0.2.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.