I do the same thing but I do it on my laptop. I have a whole folder full of what I call "snippets". Some are outlines, some are a few paragraphs, some are a few pages. They sit there off to the side patiently waiting until I can pick one of them up and start working on it. I tend to avoid fanfics for this reason. I have X days on Planet Earth. If I spend 3 days writing a fanfic, that means I now have X-3 days to finish things that I *can* publish. That doesn't meant that I discard those ideas, but I will sit them off to the side to see if I can do something with them later that is *not* a fanfic.
2 cents,
RecentCoin