I've just released a tenth application, this one for the iPhone. Novel Ideas is a very simple app that gives you a place to keep track of your ideas for novels, screenplays, plays, games, characters etc., on the go, on your phone.
I know there's a notes app on the iPhone - there's even plenty of other list apps out there. But this one is designed for the way I want to keep track of things as a writer.
Novel Ideas has four fields: -
The list is grouped by Format, so you see all your "Novel" ideas in one group, all your "Screenplay" ideas in another, etc. You're free to enter whatever you like as a format, so you're free to have as many groups as you need. I even use it for characters, putting the idea for the character as the title, the nature of the character (Hero, Villain, etc.) as the genre, and then use "Character" as the format, ensuring that the grouping in the app use "Character".
The app can export the list to a text file, so if you want to get your ideas out to another application, you can do that too.
For me, it gives me a separate place to look after all my writing ideas, away from all the other generic apps out there. It's a tiny, simple app, but I know it's always there ready for inspiration to strike.