I'm not a big fan of Instagram. Most people seem to use it as a vehicle for inflicting more selfies and food pictures on a world that isn't suffering from a shortage of either, and I won't use my phone to take a picture if I have a camera available.
There are some photographers who are creating interesting work within those limitations, of course, but it's mostly not the kind of picture I want to take. With one exception -- I've become fascinated by the square photo, especially for photographing cars and reflections. Or cars and reflections, as in these two pictures. The smaller scope seems to make the shapes more abstract somehow and I love the effect.