Network engineer here... I've been toying with this idea a little bit... Developing a hosted voip service using twilio and openvbx or freepbx. The hosted service could use hardware voip phones and/or mobile apps to utilize voice services. As twilio works, you would charge your users/businesses a pay as you go model. Twilio has an amazing API set and I can see the possibilities. The demographic would be focused in the public sector (schools, colleges, etc) and private sector (banks, Healthcare, corporations, etc).

Since so many people have smart phones, why not develop a hosted voip solution that utilizes it's users smartphones and allows them to take business calls on their cell phones, computer soft phones, tablets, etc. Even if they have a physical voip phone that receives calls and they decide to answer with their personal cell phone instead.

This is just one of the ideas that have been brewing in my head.

I'm a network engineer that works for a consulting company. So I see the current demand and businesses are paying a ridiculous amount of money for enterprise grade hardware that doesn't even provide the feature set I described above.

Maybe I just need some feedback on this idea??