I also wish Google would allow some kind of intent resolution based on, say, regex matching of the voice recognition result. I want to be able to register phrases like "OK Google, turn on the lights" or "OK Google, set the temperature to 25 degrees" and allow my app to handle them (and yes I do actually have all my lights, thermostats, etc. controllable from my phone)

My wife's Highlander Hybrid has a remote start, and I would love to be able to say "Ok Google, start the car" [+].

[+] The vehicle has a GSM adapter to allow us to start the car both through an iOS app, and a python script I wrote against their private API.

I think Commandr would let you do this https://play.google.com/store/apps/details?id=com.RSen.Comma...

"OK Google, Start Car", and write your custom Car app?

I think Tasker and AutoVoice would work [1].

[1] https://play.google.com/store/apps/details?id=com.joaomgcd.a...