Oh, as noted in the comments below, there's also 'Messenger for UWP', which takes the glitchy Facebook Messenger web view data above and puts a complete new UI/skin on it, along with detecting new messages and throwing up Windows 10 notifications:
Oh, as noted in the comments below, there's also 'Messenger for UWP', which takes the glitchy Facebook Messenger web view data above and puts a complete new UI/skin on it, along with detecting new messages and throwing up Windows 10 notifications: