Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Mati - Online identity verification platform for fast-growing companies. Increase safety on your product, and comply with KYC / AML regulations.
VerifyKit - Enables quick access to your web and mobile applications.
NoPass.me - Open-source identity verification
Twilio - Brings voice and messaging to your web and mobile applications.
RapidVerify - Verify identity/income instantly.