These days, if you own a mobile phone (and 75% of the WORLD does) there is a decent chance you have the capacity to be a photographer. BUT you might not be a very good one and putting on an Instagram filter isn't the only way to try and make your pictures better.
While plenty of apps abound and we do love Instagram, getting a handle on the basic rules of composition and understanding some of the important camera functions built right in to your iPhone can help you create MUCH better images. And then they will look even cooler when you add a filter...or you might not even need one.
Here are some tips to start you on your journey, but keep in mind the most important thing to improving your photography is to go out and take pictures, go home study and critique them, and then repeat.
And that was long before the digital age, now that number is probably closer to 100,000. So get out there and shoot.
Your iPhone camera interface - this is how it should look. HDR On and Grid On.
Click the options button in the middle and then slide them on - but make sure in Settings that you are saving both originals and HDR versions of your photos.
Use the manual focus option - don't just let the camera decide! Use your finger to select where you want the camera to focus and expose for. Sometimes when a picture looks too dark or too light try focusing on a different part of the image.