All the facts in the QI library are drawn from our books: The Book of General Ignorance (2006), The Book of Animal Ignorance (2007), and The QI Book of the Dead (2009). We've re-organised them into dozens of different topics and bound them up into the volumes you see on the app's bookshelf. The quotations on the pinboard are from Advanced Banter (2008), the QI book of quotations.

You certainly can. You'll find all the books we've used to build the app, alongside our newest releases: The Second Book of General Ignorance and The QI 'H' Annual at the QI Shop, or at faber.co.uk.

Send us anything you find interesting: if it interests you, there's a good chance it'll interest others. The best facts are concise, surprising and written as clearly as possible.

When you send us a fact, we've built in a feature that requires you to submit some supporting evidence. This can be either some text or a reference from a book, a website link, or a picture you've taken. Please make sure your sources are as authoritative as possible – trivia sites or un-referenced 'cut-and-pastes' from Wikipedia won't pass the QI test.

Once you've filled in the evidence and submitted your fact, it goes to the fact databank. We'll be able to see it but the other app users who rate your facts won't.

Once you've sent the fact in to us it goes through our moderators, so we can prevent people from posting abusive, offensive or libellous material. We'll also screen out any obvious errors. Once your fact's made it through, it will appear on other app user's devices who can then rate it on how interesting it is.

Before too long we'll have a chart of the Top Ten facts of the week (as rated by other app users) on our website, at www.qi.com/app. Keep an eye out for future updates to the app which will allow you to see ratings for your facts individually.

By sending things in to us you're giving us permission to read them and use them in the future if we find them really interesting (which I'm sure we will).

We'd much rather you only saw things you've never seen before. However, if your facts are good enough to make it into our Top Ten you'll be able to see them on our chart at http://www.qi.com/app.

If you see something wrong in the user-generated bit of the app – the 'Rate other people's facts' section – then the best way of flagging it up is by going to this special section of the QI website and mentioning it on the talkboards at http://www.qi.com/app. If you've found something wrong in our material (i.e. in the books on the shelf), write to elves@qi.com and tell us about it. If you spot any technical problems with the app, get in touch via the Contact form on this website.

The QI apps for iPhone and iPad use Google Analytics to collect and aggregate non-personally-identifiable usage data. The data helps us to improve the app by developing the features people use most often. No identifiable information such as personal details, device identifier, location, or similar is sent. For example, we can see the total number of people who have looked at chapter 3 of '20,000 Leagues Under the Sea', but we cannot see any information about who those people are.

They are a band of researchers, hacking their way tirelessly through the swamp of ignorance, tracking down facts and dragging them back to civilisation one by one.