Twilio Connect is an easy way for developers to obtain authorization to make calls, send text messages, purchase phone numbers, read access logs and perform other API functions on behalf of another Twilio account holder.
This service lets users buy their own Twilio credit so that there is no cost to you, the developer, for their Twilio usage. You prompt customers to create Twilio Connect accounts, and they pay for the time they spend on the phone from those accounts of their own.
As an example, imagine you want to create an application that allows your customer to forward phone calls. You could do this, have the usage billed to his or her Twilio account, and also access his or her logs to provide detailed call analytics.