TCP Port Checker
When I started Apache server, there was a process or service, which ran on port 80, so it blocked the port and the idea for this application came.
There is Windows built-in netstat function, which can be used to track all of the different states of the active connections, but I decided to write a tool for me.
The tool idea is to make connection to given TCP port and if connection is successfull then the port is free.