ILSpy - ICSharpCode. Decompiler. Console..
Decompiler.com - Online Java and Android decompiler. Just drag and drop .JAR or .APK file and browse decompiled content online.
dnSpy - .NET assembly editor, decompiler, and debugger
.NET Reflector - .
Java Class File Editor - classeditor - tool to edit class file binaries
IDA - The best-of-breed binary code analysis tool, an indispensable item in the toolbox of world-class software analysts, reverse engineers, malware analyst and cybersecurity professionals.