Night mode is cool - you know it, we know it.
It's that extra option which replaces as much of your screen as possible with darker colours, making it less bright when you're trying to read at night or in a place where the flow of your display might be distracting. It can also be easier on the eyes for extended reading, like in an e-book reader.
The option to switch between day and night modes is most welcome but unfortunately rarely offered by major apps. You can get the effect of it, to some degree, with a third party screen dimmer, but that can compromise the viewing experience.
So it's exciting news to hear that Twitter might be working on a legitimate night mode for their mobile app. It seems a darker theme has popped up in the latest Alpha release of the app and you can see an example of it through this link.
The presence of that theme doesn't mean that we're definitely getting the option to swtich back and forth between different looks for the app but it's a step in the right direction.