Based on the users' reviews, here are three cons and pros for the Facebook Messenger app: **Cons:** 1. "Glitches and crashes frequently happen, frustrating to use and losing messages." 2. "Too many unnecessary features and ads, making it cluttered and annoying." 3. "Lack of customization options, not able to personalize as desired." **Pros:** 1. "Easy to use and navigate, intuitive interface for instant messaging." 2. "Reliable for group chats and file sharing, seamless experience." 3. "Good security features, feel safe sharing personal info and messages." Note: The phrases are limited to 15 words each, and I've tried to summarize the common concerns and praises from the users' reviews.