I've read this book that has tips on how to live healthy. Forget the fact that there are many like it out there, that's not the point, and it's not about specific book. Now I am just curious how does that process work.
If I were to create an app that uses principles from that book, or any other for that matter, would that be infringing on the book? I mean could the writer of that book be able to sue and stuff like that? I know that would 100% happen if I were writing a book but does it cover wide variety of things like apps? I am not saying that I want to write in the app that those were my principles, not at all; just use those principles to calculate things.
Sure, in millions of apps today no-one is likely to notice it, but I would like to know is this considered illegal or do book copyrights even cover apps?