A simple app to communicate using serial (COM) ports.
It can detect avaiable ports in OS and configure it's parameters.
It has split view between sendind and receiving - you can resize it as you want!
It's written all in Java, using Java Simple Serial Connector, so it works also on Linux!
Currently it's only in Polish - you can create a new branch and translate all hardcored strings by yourself.
Or you can extend this project and add multilanguage functionality - don't forget to start a pull request then!