https://www.eatabit.io is built on it. We were one of their first beta clients. We used every M2M carrier previously and Twilio is easily superior in cost & reliability. The cellular data space has alot of problems especially with roaming: cell phones transparently switch between networks but data SIMs have a very limited set of networks they can operate on. If Twilio can get VZW access on these SIMs they will have a very strong product. As it stands, coverage is limited.