Latest Facebook Messenger 126 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; U; Android 4.1.1; pt-pt; Vodafone 975 Build/JRO03C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.1 Mobile Safari/534.30 SVN/310HGG1 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 4 Smart 3
Mozilla/5.0 (Linux; Android 7.0; SM-G925F Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/61.0.3163.98 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 7 Galaxy S6 Edge
Mozilla/5.0 (Linux; Android 6.0.1; SM-J700H Build/MMB29K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 6 Galaxy J7
Mozilla/5.0 (Linux; Android 5.1; LENNY2 Build/LMY47I; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/43.0.2357.121 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 5 Lenny 2
Mozilla/5.0 (Linux; Android 5.1.1; SM-J500FN Build/LMY48B; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/47.0.2526.100 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 5 Galaxy J5 (2015)
Mozilla/5.0 (Linux; Android 5.1.1; LGMS330 Build/LMY47V; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/59.0.3071.125 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 5 K7
Mozilla/5.0 (Linux; Android 4.4.4; SM-E7000 Build/KTU84P) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/33.0.0.0 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/126.0.0.9.84;] Android 4 Galaxy E7
Mozilla/5.0 (iPhone; CPU iPhone OS 9_0_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Mobile/13A404 [FBAN/MessengerForiOS;FBAV/126.0.0.28.75;FBBV/64550700;FBDV/iPhone5,2;FBMD/iPhone;FBSN/iPhone OS;FBSV/9.0.1;FBSS/2;FBCR/Telekom.de;FBID/pho iOS 9 iPhone 5