That's a solid list of editing apps, I've used a few of them myself. Snapseed is definitely underrated. But honestly, editing photos is only half the story. Lately I've been more curious about what people are actually doing on Instagram, not just what they post. That's when I started looking for an instagram activity tracker. Not to spy, just to understand patterns and see what's public without logging in all the time. Some tools let you view profiles without leaving traces, which is useful. The apps you listed make photos look great, but tracking activity is a whole different game.
RE: 10 Indispensable Mobile Applications Using Instagram Phenomenons