Yes, I admit, I do not have a smart phone, I rely on a cheap phone that my older coworkers like to call a "dumb phone." My list of reasons to actually invest in a decent phone has been expanding due to my business's development over the past couple months, but in the mean time, I will just fake having awesome apps so my friends think I'm at least a little cool.
Sure, you can't post your photos on Instagram even if you make them look like one. But you can at least post them on your Facebook timeline and that's practically the same...
It takes only a couple minutes in Photoshop to take a regular rectangular image and turn it into a cropped square Instagram replica.
For quick and effective cropping, adjust the canvas size by going to Image -> Canvas Size
Then change the canvas size by replacing the width and height with the numbers of your choice. Obviously choosing the same number for both so that you make your Instagram square.
I chose to make mine a 10 inch by 10 inch because I liked the height of the image already.
For this particular faux Instagram I chose to add a common effect I see on many Instagrams, a vignette.
To do so you go to Filter -> Lens Correction -> Custom
Adjust the intensity by using the amount slider in the Vignette section. Click ok to save your changes and edit your new image as normal to your liking.
And Wah lah. Instagram.