Latest Facebook Messenger 136 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; Android 7.0; SM-G935F Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/60.0.3112.116 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/136.0.0.8.90;] Android 7 Galaxy S7 Edge
Mozilla/5.0 (Linux; Android 6.0; T07 Build/MRA58K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/60.0.3112.116 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/136.0.0.8.90;] Android 6 Liquid Zest 4G
Mozilla/5.0 (Linux; Android 5.1; HUAWEI CUN-L01 Build/HUAWEICUN-L01; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/62.0.3202.84 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/136.0.0.8.90;] Android 5 Y5II
Mozilla/5.0 (Linux; Android 5.1.1; SM-J120FN Build/LMY47X; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/60.0.3112.116 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/136.0.0.8.90;] Android 5 Galaxy J1 (2016)
Mozilla/5.0 (Linux; Android 4.4.2; pt-PT; 4013X Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/136.0.0.8.90;] Android 4 One Touch Pixi 3 4"