Pic Tap Go // A constant go-to for me! I already use Rad Lab for my blog photos and love using the same filters on my iphone photos as well. The layout is beautiful, intuitive and the app gives you a full size preview of your filters in action, plus layering other effects is a breeze. You can also save your recipes for future use and the app automatically stores your most used filters in a "my style" tab - love it!! Some of my favourite filters include: bright-side, crispity, flare up, sugar rush and fade to grey. For black and white? I love using powder!
VSCO Cam // This was my go-to app prior to discovering Pic Tap Go. I still love using this one though. Their filters give photos an instant editorial/very Kinfolk friendly look and the app has a thriving community for artists and photographers.
Afterlight // I often pull my iphone photos through afterlight for quick tweaks. I love using this app for brightening, sharpening and adding a little colour saturation to my photos. I also love their light leak and texture filters! So, gorgeous. You can see a recent example here!
Over // In a word? Awesome! This app allows you to apply designer like texts, sayings and graphics to your photos. Just check out their instagram feed - you'll be hooked!
ABM // I'm sure most of you already know/use this one. But I love "A Beautiful Mess" and I love their app. Adding doodles is such a fun way to give your photos a personal and whimsical feel... you can see a few of my examples here & here!