I want the default to be night mode. There will be no light mode, only dark, I find it more convenient and so does my friends so we think that the next apps we build should have a dark background instead of light. But we want to know the ups and downs before doing this and has anyone else tried it before.
Is there an example of an app like this? What happened? Does it decrease the usage or increase it? Why?
Look up the "Locus of Control" part of Shneiderman's "Eight Golden Rules of Interface Design" http://faculty.washington.edu/jtenenbg/courses/360/f04/sessions/schneidermanGoldenRules.html
"7. Support internal locus of control. Experienced operators strongly desire the sense that they are in charge of the system and that the system responds to their actions. Design the system to make users the initiators of actions rather than the responders."
Pretty much people like to be in control of the app, forcing the app to do things without the user initiating it can be both confusing and irritating. Instead make the option to switch into night mode simple and obvious. That way the user's that don't want night mode aren't forced into it but those that do want it can easily enable it.
I don't think there's a conclusive detailed study on usage of night/day modes. I have generally seen developers preferring night mode for their editors/IDE. As an example, you can have a look at various types of night mode here - ColorSublime
As far as readability is concerned, there are studies which demonstrate that dark colored text on lighter backgrounds are easier to read. Related article - On readability of inverted color schemes
Also, there's another discussion about the usage of high contrast mode - Is high contrast mode useful?
Hope this helps.
