remixicon
· Remix Icon is a set of open source neutral style system symbols elaborately crafted for designers and developers. All of the icons are free to use for both personal and commercial.
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 remixicon-3.5.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.