Case Study: Kitestring secures 100K+ users with Twilio Voice and SMS

Kitestring Keeps Hundreds Of Thousands Of People Safe With Twilio SMS

Kitestring is a personal safety check-in service founded in 2014 by Stephan Boyer to help people confirm they got home safely via simple SMS. The core challenge was delivering timely, reliable messages at scale—timing is critical because delayed or failed messages can cause false alarms or miss real emergencies as the user base grew rapidly after launch.

Kitestring built its service on Twilio Messaging and Voice, integrating the API in about four hours to handle verification, check-ins, and emergency contact alerts. The result: dramatically better engagement (8x retention versus email), reliable delivery at scale (100K+ SMS per month, 117K in a peak month), fast time-to-market and seamless growth into new markets (U.S. and U.K.) with minimal infrastructure overhead.

Kitestring

Stephan Boyer

Founder