There's a great deal of interest in controlling Kodi and apps like it using Alexa, however to make that work, the app needs a remote server that can connect to Alexa's cloud servers. At present, the only way to set this up is using an elaborate server system, like this: http://www.howtogeek.com/249336/how-to-control-your-kodi-media-center-with-an-amazon-echo/
It seems to me that Trakt already has almost all the tools to make this work without needing an elaborate setup. You have the library of the Kodi user. You have a connection from Kodi to the internet. What you still need is a way to send commands to Kodi beyond setting watched status, a way to enumerate Kodi instances (if you don't already have this), so you know which Kodi you're controlling, and an integration with Alexa, which I presume can be found in that link I included. In other words, because of your setup, much of the infrastructure is already there.
Plus, if you put this functionality behind a donor wall, I imagine a LOT more people would donate.