The new Twilio Client is pretty damn impressive:
In particular, the voicemail feature could be a great way to integrate audio recording into form submissions.
Yea, we definitely want to expand Twilio's functionality in the future. They do a lot of cool things with their API. It's definitely on our list to add additional features to the Twilio Add-On. Currently we are working on Gravity Forms v1.6, some other Add-Ons and a new unrelated product but we will get around to updating the Twilio Add-On as we will be updating all of the Add-Ons to add additional features.
Cool, it is fun watching GF get better and better, I'm looking forward to 1.6.
I actually wrote to the Twilio guys too, asking if there is any chance of them adding video to the new Twilio Client - for me, GF integration with that would be the holy grail, allowing users to submit a webcam message along with their form, the potential for stuff like identity verification, customer testimonials, age verification etc would be massive.
Good luck with your mystery product.
I did this too. Awesome.