I've been using it for a little while, it works great although there is some room for improvements, the notifications are not working too well, address book is useless, there is no auto-join option for channels. Other then that I actually love this tool. Hope the dev will take this feedback to mind!
I have been using this for a couple months now, and it's really great. I highly appreciate having a look at my chat (+ having access to many other Twitch features) without opening a resource consuming browser !