I've used Plivo in the past and was happy with the results. Since you mention Twillio, I'm assuming you're okay with a development platform and are not necessar

I've used Plivo in the past and was happy with the results. Since you mention Twillio, I'm assuming you're okay with a development platform and are not necessarily looking for a consumer product. Plivo did recently roll out PHLO, which allows building a solution with little or no programming.