What it does now: Wastes your time, mostly. Lets your eyes glaze over as you scroll through the news feed while walking, on public transportation, or even while driving. Eliminates pesky "thinking time".
What it could do: With the addition of facial recognition software, the Facebook app could be a veritable Pokédex for humans. Don't recognize that person who is speaking at your face with a tone of familiarity? Hold up your phone's camera and scan him/her quickly to learn that it's "Claire Degraw, with whom you became Facebook friends after you both attended an event called 'STEVE'S 22ND BARFDAY'."
What it does now: Tells you the name and recording artist of any song that you hear but are too embarrassed to ask about. Also, has access to an eerie amount of seemingly unrelated data on your phone.
What it could do: Tell you how you know the song.Allow Shazam to cross-reference a song's title with your Netflix history and and learn that it was the second song in the credits to The Devil Wears Prada, which you watched (shame on you) last Tuesday. Take it a step further and allow Shazam to constantly analyze audio, plus give it access to your social media accounts. Where do you know that song from? It was playing while you were attending a Facebook event called 'STEVE'S 23RD BARFDAY: BARF HARDER'."
What it does now: Allows users to send each other photos and videos that disappear in 10 seconds or fewer. Sends misinformed parents and newscasters into hysteria.
What it could do: Connect to a 3D printer or scanner and send objects that dissolve in seconds. Why send a dick pic when you can send an actual physical model of your dick? It won't last long enough to be incriminating, just long enough to establish a sense of scale.
On a related note, it would be nice if Snapchat used image analysis software to create a "Dicks Filter" that can be toggled on or off.
What it does now: Takes square pictures. Allows idiots to believe they are photographers.
What it could do: Include some photo effects that don't make your photos look like they were taken with a low-quality camera from half a century ago that most Instagram users have never seen nor heard of. Team up with Photoshop to add some crazy, powerful photo effects like a "Brightness/Contrast" option.
Also, use facial recognition software to automatically delete selfies before they are posted online.
What it does now: Forms addictions. Kills time. Convinces people who have never played a video game that they are playing a "really great video game".
What it could do: Replace all gameplay content with a download link to a Street Fighter II emulator.