[s3e22] She's Got Us -

While there isn't a specific "gadget" or "app" highlighted, the episode focuses on the following crucial investigative elements:

: Dr. Daniel Charles is brought in to help Lindsay and Halstead connect with Polly, who is disoriented and heavily traumatized. [S3E22] She's Got Us

This episode is also notable for the of Officer Sean Roman, who learns his injuries might be permanent, preventing him from returning to full patrol duty. Chicago P.D. 3x22 "She's Got Us" Recap - Lady Geeks Media While there isn't a specific "gadget" or "app"

In the Chicago P.D. episode (Season 3, Episode 22), a significant "useful feature" or plot device is the traumatized young survivor, Polly Carlson , who is the key to identifying the killer after her family is murdered. Chicago P

: Antonio and Olinsky investigate Horizons , a pyramid scheme/self-help group that the victims were involved with, looking for potential suspects.

: Polly mentions a specific location she needs to visit, which becomes the primary clue leading the team to a breakthrough in the case.