TextBee
Free tierOpen sourceFrom the lab
Open-source SMS gateway that runs on your Android phone
Twilio
Paid
Cloud APIs for SMS, voice, WhatsApp, email and verification
The gist
Twilio provides pay-as-you-go APIs to send SMS, WhatsApp messages and email, make voice calls and verify users. It is for developers and companies that build customer communication into their apps.
Twilio alternatives
Compare all 3 →The Gist, weekly