Facebook has its own official app -- plus about 17 other official apps, including the standalone Messenger app -- but it might not be the best Facebook app for you.
Alternative Facebook apps such as Friendly and Swipe ($100 at Amazon) for Facebook can give you the experience you've always wanted -- they use less of your phone's battery and data, give you more privacy (even though Facebook claims that it's ) and combine Facebook and Facebook Messenger into one app.
If you hate switching between Facebook and the Messenger app to carry on your Facebook-oriented chats, you might want to check out Friendly (Android and iOS), a free, ad-supported app that fixes this first-world struggle. Not only does Friendly put the Facebook back in Facebook Messenger by combining the two into one apps, it offers a more robust Facebook browsing experience. It lets you sort your newsfeed (you can order posts by freshness, popularity or close friends) and filter your feed by highlighting or hiding specific keywords.
Friendly offers custom colors, text sizes, and the ability to add a passcode or Touch ID lock for extra security. If you're looking to save data and time, you can turn on the app's "block images" feature to browse a text-only feed. Friendly is ad-supported, but you can purchase a permanent ad unlock for $1.99.
Puffin for Facebook
Puffin for Facebook (Android and iOS) is a free app created by the developers of the speedy, low-resource Puffin Web Browser app. Puffin for Facebook uses Puffin's cloud rendering technology to offer a speedy, low-resource Facebook experience -- the app even tracks your monthly data savings as you use it.
Puffin for Facebook is a web wrapper, which means it's actually a browser app made just for the Facebook mobile site. This means that it offers the same features as Facebook's mobile browser, including built-in Facebook Messenger, but you'll see an ad for the Messenger app before you can access your messages. This may not be the fanciest Facebook app -- it's just the mobile site, after all -- but it can help improve your experience drastically if you're using an older device or if you have a tight data cap.
Swipe for Facebook
Swipe for Facebook offers a more customizable Facebook experience. The Android-only app features a night mode, multiple color schemes and Material Design visual tweaks, though some of these features are only for the paid Pro version.
Like Puffin, Swipe for Facebook is a lightweight web-wrapper app, so color schemes and visual tweaks aside, it's a lot like using the mobile version of Facebook. You'll be able to browse your timeline, edit your profile, approve friend requests, and block images to save data, and the app also has extra security options like a PIN or fingerprint lock. If you'd rather use the Messenger app to do your chatting, Swipe for Facebook will also let you choose your messages client, which is a nice feature. You can access your messages from within the app or follow links to the outside Messenger app.