Some useful software
First of all, sorry for writing in English since my office PC doesn't have Myanmar keyboard.
which is a java decompiler. Useful and elegant when you need to decompile your source code (class files)
it is good for web developer to keep track of the server response such as json strings, server's status response. It is a must for web developer these days.
In one of my projects, I had to use a third party DLL. No source code. I used it to decompile it. It is not free. For me, it is good enough.