One Seven Seven

Tons of live filters, controls & features. Can even edit existing photos using the same tools. The UI is not overly complicated like other apps. Photos save directly to camera roll. Could use some aspect ratios like 9x16 & 5x7. Currently has the standard 3:4, and 1:1. There was a recent update, 2016-September, so the developer does work on the app to improve it. If thinking about BW photos with your iPhone, this might be the only app you need.