HoloLens App For First Responders written by Engg. Book May 30, 2018 HoloLens App For First Responders HoloLens App For First Responders was last modified: May 30th, 2018 by Engg. Book 0 comment 0 Facebook Twitter Google + Pinterest Engg. Book Leave a Comment Cancel ReplyYou must be logged in to post a comment.