If you're a Facebook user, you're probably aware by now that you can no longer send and receive messages from within the mobile app. The company now requires you to use the standalone Messenger app for mobile chats.
I suspect most users had the same reaction I did: Uh, no. Why should I install a second app just so I can trade the occasional message with a Facebook friend? It reminds me of when Apple ripped podcast management out of the Music app and forced users into a seriously awful standalone app.
Fortunately, there are two ways to deal with this.
First, you can open Facebook in your mobile browser, sign into your account, and access the service via its Web interface.
There are a few advantages here, not the least of which is integrated messaging, just like you're used to. This browser-based version also provides a nearly identical feature set and navigation menu, so there's virtually no learning curve. And as noted over at ITworld, the Facebook app can put a dent in your battery life, meaning you're actually better off deleting it and relying on the Web version instead.
So to make that your permanent option, just bookmark the mobile Facebook site (m.facebook.com), then add a shortcut to your Home screen.
Your second option? Suck it up and use Facebook Messenger, especially if you're a heavy chatter. Annoying as it is to have to switch to a different app, Messenger itself is fairly robust, offering easy ways to create groups and send photos, videos, and even voice clips. It's chock full of emoji (or "stickers," to use FB parlance), if you're into that sort of thing, and you can use it to voice-call other Messenger users at no charge.
In other words, before you abandon Facebook in a huff, at least give Messenger a try. You might find it useful -- and at just 35MB (for the iOS version, anyway -- Android size varies), it's a reasonably compact app.