Gander
· Gander is a simple in-app HTTP inspector for Android OkHttp clients. Gander intercepts and persists all HTTP requests and responses inside your application, and provides a UI for inspecting their content.
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 gander-3.1.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.