You can actually view messages on the mobile web app (or you could earlier today, anyway). On my phone, clicking on messages tells me to download messenger. If

You can actually view messages on the mobile web app (or you could earlier today, anyway). On my phone, clicking on messages tells me to download messenger. If I ignore that and hit all messages, it nags again, but eventually does it. FWIW, I discovered this because Messenger would not show me a group chat that I was added to by co-workers (who I'm not friends with on FB). Edit: just realized you were referring to the app, not the site. My mistake.