How to Convert .Jar to .Apkby Mitchell White ; Updated September 28, 2017
APK is the file format for applications on the Android operating system, which is a popular system used in the Android line of smartphones. If you have an APK file that's stored inside a Java Archive, or JAR, you'll need to decompress the JAR to get the APK files you want. You can use some free tools available online to open the JAR. These can include programs as well as archive sites.
Download and install WinRAR. Right-click on your JAR file. A set of drop-down options will appear. Select "Extract here." The APK file will appear in the same folder.
Download and install Bitzipper. Double-click the JAR file to open it and reveal the APK inside. Click and drag the APK to your computer's desktop to convert and decompress the JAR to APK. This program is free to use for a month as a demo.