It's wonderful having access to the millions of functions most modern DAWs like Logic Pro, Cubase, Pro Tools and Ableton Live provide. But, honestly, sometimes a simple, single task app might be all you need when it comes to choosing which port you receive and send MIDI signals from and to.
Ícaro Ferre, the brains behind Spektro Audio has released version 1.0 of MIDIrouter, which does what you'd expect. Forget complex menus and a multitude of buttons or displays. This easy to use app gives you two drop down menus. One to choose the MIDI In port and the other to choose the MIDI Out port. Done. MIDIrouter simply routes incoming MIDI signals from a selected input port to another output port.
So, for example, you could route MIDI from one hardware synthesizer to another, using the computer as a simple USB / MIDI host. Just download it. You never know when it'll come in handy in your studio or live performance workflow.
The only caveat is that it's currently Mac OS compatible only. Sorry Windows musicians.
Download MIDIrouter on Github here: https://github.com/icaroferre/MIDIRouter