When comparing Messenger vs QuickPic, the Slant community recommends Messenger for most people. In the question“What are the best Material Design apps?” Messenger is ranked 22nd while QuickPic is ranked 55th. The most important reason people chose Messenger is:
Allows communicating with anyone who's a friend on Facebook.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Uses Facebook friends to create a contacts list
Allows communicating with anyone who's a friend on Facebook.
Pro Read receipts
Can see who has seen each message in group messages.
Pro Easy to share posts from Facebook
Integration with Facebook makes it easy to share any interesting posts from the Facebook timeline.
Pro Great UI
User interface of the application is clean, intuitive and easy to overview.
Pro Fast performance loading photos
QuickPic displays photos ultra fast and performs better than most stock gallery apps. Developed with speed in mind, QuickPic will make working with any library of photos lightning quick.
Pro Supports multiple online photo album services
QuickPic integrates with: Flickr, Picasa, 500px, and many more.
Pro Supports hidden images
In order to hide an image, start the title with a period. This can be great for privacy purposes.
Pro Excellent file management tools
QuickPic offers excellent file management tools, with the ability to move and rename photos, users are in total control over the photo library. Easily find new photos by date or location with the grouping tool.

Pro Impressive video-player
Allows to lock a video in landscape mode and intuitive controls via swipe gestures.
Cons
Con Lack of privacy
Messenger is owned by Facebook. Based on their privacy policy, this means that any information you provide (including messages sent) are used by Facebook to profile you and sell access to your data to advertisers.
Con Lack of end-to-end encryption
Secret (end-to-end encrypted) chats are only supported in one-to-one messages, and are not enabled by default, and the encryption has not been verified independently.
Con Buggy and unstable since acquisition by Cheetah Mobile
v5.0.0, after acquisition by Cheetah Mobile, has countless bugs and basically nonoperational. This, probably, clone of original app, assembled from alternative, home-made and very low quality source code.
Con Untrustworthy
It's owned by Cheetah Mobile. That says it all.
Con Removed from Play Store in 2018 and rightfully so
