Will police notebooks become a thing of the past? Officers in New York City will no longer be keeping hand-written activity logs, as they are switching to an iPhone app:

For more than a century, the New York City Police Department has required its officers to keep a detailed, handwritten memo book while on patrol.

“It’s basically our bible,” said Officer Ramses Cruz, who joined a platoon of officers writing down patrol assignments in oversize black leather binders at a recent afternoon roll call at the 90th Precinct Station House in Williamsburg, Brooklyn.

Officer Cruz’s locker at the station house holds dozens of completed memo books chronicling his 23 years in the department, with details about big arrests, countless 911 calls and even what time he took lunch.

The memo book may be the department’s oldest policing tool, one that has appeared in countless movies and television shows and become as much of a staple as the gun, handcuffs or the nightstick.

Read more: Why the N.Y.P.D. Dropped One of Its Oldest Crime-Fighting Tools