No, didn't use any apps for this one. Just shot using the camera and standard software. But I exposed for the sky instead of the buildings. I think that's what caused the silhouettes and the vibrant colors. I've noticed that my iphone tends to exaggerate colors a bit on the vibrant side, and I'm not sure why. I never need to enhance them and if anything, I'd look to tone it down a bit if I bothered to do any PP (which I rarely do on iphone shots). That said, the colors were crazy vibrant that day, due to some apparent volcanic activity in iceland and ash in the sky.