Shield4J is a Java class and Android APK obfuscator, encrypter, shrinker and merger based on a powerful and easy-to-use online service. It supports all types of most common Java applications: self-contained Main, Java Web Start (JWS), SWT, Swing/AWT, Applets, Web Servlets, JavaFX and Android - JAR, APK, DEX, WAR. It makes your code stronger against reverse-engineering and reduces the JVM and Dalvik VM class loading time and memory consumption.
A Java class library designed to make many common actions easier, plus some of the less common ones. The original name was Multilib, hence the URL. Shortly after the project was made public, the name was found to be already occupied.