B737 flight crew reported experiencing severe turbulence while on descent.

Narrative

On the ZZZZZ arrival ATC reported that previous aircraft had experienced Moderate turbulence out of 15000 ft. ATC kept us high to try and avoid it as long as possible. Passing 15000ft we encountered severe turbulence. Our weather app on our IPAD also indicated it was severe. The airspeed varied between 210 and 225. The airplane was configured with flaps at 1 degree. The turbulence lasted for approximately 15 seconds. No over-speeds occurred and no injuries occurred. The remainder of the flight was uneventful. After blocking in; calls to dispatch; Maintenance Control; and the Chief Pilot were made as well as a maintenance write up. Maintenance completed their inspections and cleared the aircraft flight.