Since we started App of the Day on Pocket-lint, we've published 457 (now 458) individual reviews of applications for a wide range of smartphones, tablets, games consoles and, even, connected TVs.There's plenty of games among them, quite a few utilities and practical applications, and even an app made by hopefuls on The Apprentice. But we can safely say that none of them are quite like today's App of the Day.More than just a mere companion to one of the greatest comedy movies ever made, we have totally fallen in love with...Monty Python: The Holy Book of Days\nFormat\niPad\nPrice\n\u00a32.99\nWhere\niTunes\nMonty Python and the Holy Grail came out in 1975. Most of the Pocket-lint team were either in short trousers or a mere glint in their parents' eyes, and it's fair to say that those around may have laughed at the phrase, "I fart in your general direction" but little else. Not that they'd be able to see it anyway. Not only would they be unlikely to get away with standing on each other's shoulders to get into the cinema for the A-certificated showing, fake beards or no, there was no video cassette system to watch it at home.By the 1980s, mainly thanks to the proliferation of VHS and, ahem, dodgy copies of the film knocking about, school playgrounds were full of kids running around shouting "We are the knights who say... Ni!" and "It's just a flesh wound".Even today, you'll hear the occasional ramblings on whether a swallow could carry a five pound coconut. The movie means so much to so many.Therefore, Monty Python: The Holy Book of Days was always going to do well. It's an official Monty Python interactive book about the making of a treasured film. Little did we realise that it would also set the benchmark for interactive literature.The mainstay of the application is a day-by-day account of the nightmare of making Monty Python and the Holy Grail. Shooting of the entire movie famously took 28 days (for a reported budget of \u00a3229,575), so each day is represented in the app by the main scene that was filmed.This is supported by more extra material and behind the scenes content, much of which has never been seen before, than you could shake half a coconut at. There are pictures, animations, video footage, audio clips, scripts, Michael Palin's diary entries, director's notes, 360-degree rotatable props and much, much more. Although there's not a lot of text on each page, you will still find you're ploughing through so much media that it could take you longer to finish than a normal tome.You can also view some of the content on a scene-by-scene basis in chronological order (as the rest is catalogued by shooting order).And then there's an extra cherry on top for owners of the new Monty Python and the Holy Grail Blu-ray. If your BD spinner is hooked up to the 'net - and many are these days - you can sync the application to the Blu-ray disc. You will be able to control playback via the app, and it will turn to the correct section as the movie plays. It's a fan's idea of heaven.Basically, even if you have only a mild interest in Monty Python, this application is worth the three quid entrance fee. In fact, if you're a film student, we advise an immediate purchase - if only to see the hell of trying to make a movie in the Scottish highlands on a shoestring.Even if you just love your iPad and want to treat it to the best example of what an interactive book should be, this is for you. As John Cleese says in a video introduction at the beginning: "I believe we're the first to do something like this."Let's hope they're the second too... Life of Brian, please.