I think Facebook Messenger is a great app. In my mind, it's a great unifier for communication. You can use it on your computer, tablet, or smartphone. Everything works fast and there are a ton of great features. I felt naked without it on my new phone yesterday, so I installed it. After I installed it, I noticed my phone was a tad slower.
THIS WAS A BRAND NEW GALAXY S7 EDGE THAT WAS STARTING TO RUN SLOW.
I have a few friends that swear that Facebook Messenger slows their phone down, and I was a little hesitant. I now believe them after seeing it for myself. I'm a little mad, because FB Messenger is such a great app, but I'll have to live without it.
So here's where I am at. I don't have the FB app or FB messenger apps installed anymore on my main phone. So Mr. Zuckerberg, #SorryNotSorry.