There is a mild learning curve getting into this tool, but once you get it, any idiot can create some cool stuff like they were a pro musician. Thats the whole point.
It's two finger fun all the way.
The interface is crammed and looks a little daunting when you first look at it, but go find some tutorials by MG The Future on youtube and you will be up and running in 5 minutes. It's a lot of fun and very very powerful. It's great for getting your chords to be strummed (with the correct voicing) so you can apply it to a guitar VST synth.
Technically, Instachords is a MIDI effect. It takes in MIDI input and outputs notes. It's kind of a MIDI note "generator" but it's controlled by minimal MIDI notes. So it's a MIDI effect.