Latest Facebook Messenger 67 user agents:

User Agent Platform Device
Mozilla/5.0 (iPod touch; CPU iPhone OS 9_3_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Mobile/13E238 [FBAN/MessengerForiOS;FBAV/67.0.0.41.65;FBBV/28044613;FBRV/0;FBDV/iPod5,1;FBMD/iPod touch;FBSN/iPhone OS;FBSV/9.3.1;FBSS/2;FBCR/;FBID/p iOS 9 iPod Touch 5
Mozilla/5.0 (iPad; CPU OS 9_3_4 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Mobile/13G35 [FBAN/MessengerForiOS;FBAV/67.0.0.41.65;FBBV/28044613;FBRV/0;FBDV/iPad3,3;FBMD/iPad;FBSN/iPhone OS;FBSV/9.3.4;FBSS/2;FBCR/;FBID/tablet;FBLC/vi_VN;FBO iOS 9 iPad 3