Darkroom photography is still a thing but it’s not a practice that many people can get into, no matter how interested they are. There are specific supplies, space, and a good deal of time one needs to support that hobby. Thankfully, there’s an app for that. Darkr is the app that lets you develop digital images as if you’re in a physical darkroom.
I must tell you from the door that this is an Apple only app, sorry. It’s so neat though that I still wanted to bring it to your attention (in hopes that we could start a push for an Android version). This app only develops in black and white but you get to decide how saturated and exposed the image is, among other things.
The app gives you a variety of tools to help you create the best photo, using some older practices, updated for the modern age. It’s a fun way to look at smartphone photography. This app is free but has paid “pro” options.