So far I have got 3 ways to have Amazon Echo support, each with their own pros and cons:
The update of Home Remote - Activator for OS X (out NOW!) can interface with the IFTTT Maker Channel as it has a webs server built in. This means you can port forward your external IP to the Home Remote server and then use that to call your Indigo actions. A video of this method can be seen here :
https://youtu.be/IjF7CANJNQI
Pros: It's quick to call: "Alexa, trigger my study lights on"
Cons: It's rate limited, and sometimes there is a delay.
The second method to call indigo was to write a custom skill, but as Jay noted, there is no way to send a configuration to a skill, meaning no server address or custom utterances. I will be releasing my skill on GitHub for people, along with setup instructions. You can see a video here:
https://youtu.be/RwkkHBU8MZg
Pros: It's accurate, and feels better. You won't need to create an IFTTT trigger for each actions. It's immediate.
Cons: You will need to set it up yourself, although this is only 20 minutes of following instructions.
The third way is using something like the Hue or WeMo scripts that will fake a device and then tie actions to it. I use the fauxmo Python script You can see a video here:
https://youtu.be/cSPBfL62XPU
Pros: It's accurate, fast and feels better. You won't need to create an IFTTT trigger for each actions. It's immediate, with no external network calls
Cons: You will need to set it up yourself. You are limited to 16 devices, each with an on and off URL call.