There are now hundreds of thousands of apps available for your iPhone 5, iPhone 4S, iPod touch and iPad, and, surprisingly, many of the best are free.
The following list showcases our pick of the 70 best free iPhone apps, and includes iPhone applications for social networking, travel, news, photography, productivity and more.
Most of these apps are also suitable for the iPod touch.
If your top free iPhone apps aren't covered, tell us all about them in the comments.
And don't forget to check out our iPhone 5S rumours and iPhone 6 rumours.
You can also take a look through the top 10 free iPhone apps with our nifty video.
1. FacebookThe world's biggest social network brings a tightly honed experience to the iPhone and iPod touch, but nonetheless still enables you to access your contacts, feeds and other important information. This sense of focus makes it in many ways superior to using Facebook in a desktop browser.
2. PhotoSynthWe did a bit of a double-take on seeing Microsoft's name attached to this, not least given the lack of a price-tag. But PhotoSynth is a really great panorama app; it's user-friendly and fun to use, especially when watching your panoramas take shape while you capture them.
3. RunKeeperThe prospect of Nike+ but better and for free might sound unlikely, but that's what RunKeeper provides. Previously split into 'pro' and 'free' versions, the developer now generously includes all the features in one free app.
That means you can spend no money, yet use your iPhone's GPS capabilities to track your jogging and cycling routes, and examine mapping and details of your pace and calories burned. Activities can be shared online, and treadmill runs and other exercise details can be entered manually.
4. PulseRSS has a reputation for being a rather dry technology, feeding you dull lists of headlines. Pulse flips RSS on its head, providing streams of feeds that grab your eye with photographs. It's perhaps not for the hardcore RSS crowd, but if you follow a small number of feeds, it's a great choice.
5. DropboxPlenty of apps exist for transferring content between your computer and your device, but Dropbox is free and easier to use than most of its contemporaries. Dump files you want to sync in a folder on your computer and Dropbox for your device will enable you to access them, download them for offline viewing, and, in many cases, view them.
6. National Rail EnquiriesFor anyone commuting by train, National Rail Enquiries is a handy app to have installed. There's journey planning, timetables and a location-aware 'next train home' option, along with progress tracking, so you can see when a train's likely to show up. It's not as usable nor as pretty as UK Train Times, but it is broadly similar - and five quid cheaper.
7. SkypeFaceTime is a great alternative to standard voice calls, but it's no good if you're trying to contact someone without a Mac or compatible iOS device. Therefore, Skype remains an essential download. The interface is simple and usable, enabling anyone with a Skype account to make free calls to other Skype users and cheap calls to anywhere in the world. If you're on Pay and Go, this is particularly handy, but the app also enables iPod touch users to utilise their devices for calls.
8. Movies by FlixterAlthough some aspects of cinema listings app Movies by Flixter are disappointingly US-centric (notably regarding details on upcoming movies and DVDs), it succeeds where it matters. Select a film and the app figures out where you're located, lists nearby cinemas, and displays times your chosen film is showing. Efficiency can be further increased by pinning favourite cinemas to the top of the list.
9. TonePadVirtual pianos and guitars are all very well, but purely digital musical toys are more suited to Apple handhelds. TonePad is the best of them, using a grid-based interface that enables you to turn notes on and off and compose pleasing and harmonious loops; your creations can be edited, saved and uploaded to share with other users.
10. Thomson Reuters News ProThere are many free news apps, but Reuters News Pro offers a breadth of coverage that makes it a winner. Preferences enable you to tailor the app's output to the UK, and the toolbar provides swift access to news, pictures, videos and stock markets coverage.
11. TwitterThe official Twitter app might lack some of the features found in the likes of Tweetbot, but it does provide a sleek and simple means of using the service. It also directly mirrors the latest navigational scheme on the Twitter website.
12. ComicsIn all honesty, Comics is a little awkward compared to using it on an iPad, but you won't find a better comics experience on an iPhone. The app is free, as are dozens of downloadable comics - and once you run out of those, many more are available to buy. Reading works on a frame-by-frame automated 'zoom' basis, and is surprisingly usable.
13. WikipanionThe Wikipedia website works fine on iPhones, but a dedicated app is a better bet. Wikipanion is a freebie which gives you quick access to article sections, in-article search, viewing options, bookmarking, and the ability to tweet about whatever odd fact you've just unearthed. Also, wonderfully, there are no ads.
14. EvernoteClients to access the popular Evernote service for storing notes and ideas online are available for so many platforms that we half expect a ZX Spectrum app to be announced tomorrow. On the iPhone, Evernote is efficient and usable, enabling you to rapidly scan your notes and also create new ones.
15. KindleWith iBooks on the iPhone, you might wonder why you should bother with Amazon's Kindle. After all, the app's not as pretty as iBooks, nor is there an integrated store (you buy in Safari and sync purchases to the app). However, Kindle offers a massive selection of books compared to Apple's app and the reading experience is great.
16. Around MeAround Me figures out where you are and lists local stuff - banks, bars, petrol stations and, er, Apple Retail Stores. The app's reliance on Google Maps info means there are gaps, but it's nonetheless handy to have installed when in unfamiliar surroundings, and the 'augmented reality' landscape mode is amusing, if flaky.
17. Dictionary.com - Dictionary & ThesaurusOver two million definitions, synonyms and antonyms are available in the palm of your hand with this free, offline dictionary and thesaurus. The app is fast and efficient, includes phonetic and audio pronunciation of words, and its interface seems perfectly suited to the iPhone.
18. Air Video FreeAir Video Free can stream (and convert as necessary) video from any computer running the free Air Video Server. You only get access to a small number of items per folder or playlist, but some careful planning can get around that limitation.
19. Adobe Photoshop ExpressIf you're looking for Photoshop-style power, Photoshop Express won't impress. However, if you're after a quick, free, highly usable tool for making edits to your iPhone photos, Adobe's app is ideal. Use it for cropping, straightening, exposure adjustments, colour effects, sharpening and more.
20. iHandy Level FreeOne of the tools from the excellent iHandy Carpenter toolkit app, iHandy Level Free turns your iPhone into a spirit level. By default, it'll show just how wonky your device's accelerometer is, but tap the calibrate button and you get an accurate and great-looking level.
21. PocketThe service formerly known as Read It Later enables you to save pages from websites, to read them later, bereft of the advertising and other junk on the original page. The service is free, as is the Pocket app, which downloads your articles, so that you can digest them without a web connection.
22. PCalc Lite"But I've already got a calculator on my device," you might argue. True, but we'd recommend stashing the default Apple app in a folder and replacing it with PCalc Lite. The reason: this is without doubt the finest free calculator for iOS, with a great interface and plenty of options. You can also bolt-on features from the paid version via in-app purchases.
23. iBooksEffectively iTunes for books, the app combines a reader and store, in Apple's typically usable and integrated fashion. Usefully, iBooks includes PDF support and bookmarks automatically sync across devices.
24. Red LaserThe Red Laser bar-code scanner is pretty accurate, even if you're still saddled with an iPhone 3G. It's great for checking prices while shopping, and also enables you to get your media collections into Delicious Library if you make use of AppleScript.
25. eBay MobileOn using eBay Mobile, there's a good chance you won't go near the eBay website again. The app is fast, has great saved searches (which flag new finds), and enables you to create listings. The last of those things is also improved by the built-in bar-code scanning.
Before reading on, why not check out our demos of the best photography apps for taking pictures and editing them on your iPhone:
26. Tube MapAt its most basic, Tube Map is a London Tube map on your device, for free. In landscape, even the ads get out of your way, which is rather nice. And if you've a web connection, the app also provides live board info, a station finder and a route calculator.
27. Google Earth"Hold the world in the palm of your hand," says Google about Google Earth, which enables you to fly across the planet by swiping your finger. More integration with content and features from Maps would be good, but Google Earth's Wikipedia articles and a Panoramio layer at least ensure it's a great app for seeing the world from your living room.
28. XE CurrencyXE Currency is a fine example of an app that does what it needs to, without fuss. You configure a list of currencies, and it shows current conversion rates. Double-tap a currency to set its base rate or to define values for custom conversions.
29. ShazamShazam is an app that feels like magic when you first use it. It's deceptively simple—hold your iPhone near to a music source, and wait while the app listens and tells you what track is playing. But the sheer technology behind this simplicity is mind-boggling, and while Shazam doesn't always guess right, it's worth a download.
30. BumpAnother contender for the 'surely, that's witchcraft?' award, Bump enables you to select up to four contacts, then 'bump' your device into another iOS device running Bump to transfer details, or to compare contacts. And, yeah, we know there's an email-based 'share contact' option in Contacts, but where's the fun in that?
31. Yell.comAs you might expect, Yell.com enables you to find local stuff. Select from a bunch of built-in categories or type in your own term for a list of local amenities, and use the map to navigate. Avoid the clunky augmented reality view, though.
32. BBC NewsBBC News has a mobile website that works very nicely in Safari. However, the BBC News app is designed to give you quick access to breaking stories, complete with playable videos and zoomable text. The navigation's a tad on the quirky side though.
33. Find My iPhoneFor the paranoid souls out there (or the unlucky ones who've had their devices pilfered), Find My iPhone is a must-have download. Assuming you've a 2010 or later iOS device, you can set up a free account and locate your devices within seconds. (Note that older devices can also be added to Find My iPhone - you just need a recent one to get things going.)
34. Dragon DictationFed up of typing on the tiny iPhone keyboard? Use Dragon Dictation instead, which happily converts your speech into text (with slightly spooky levels of accuracy for a freebie app). You can even punctuate ("Comma! Full-stop!"), and when you're done the app enables you to fire your thoughts at Facebook, Twitter, Mail or the iOS clipboard.
35. iHandy Torch FreeIt's a torch! It's a cheesy neon light! It's a hypnotic spiral effect! With slightly annoying ads! (In reality, iHandy Torch Free is a mostly a handy app to have installed in case you get up for a midnight snack or toilet visit, don't turn on the light and want to avoid smashing your toe annoyingly hard into an unruly cupboard.)
36. TVGuide.co.uk TV GuideTV Guide is an app that's come a long way. At one time, this was a disappointing UK TV listings app. Today, it boasts now-and-next and scrollable listings views, reminders, and calendar, Twitter and Facebook integration. Only avoid if you hate TV or don't live in the UK.
37. Zoopla Property SearchThere are loads of property search apps on the App Store, but Zoopla is the best of them. Its listings are comprehensive and there's also local market data, including local sale prices and estimates on market value. The location button is a bit rubbish, but the app soon finds properties when you manually type a location.
38. IM+If you're an instant messaging fiend, IM+ gives you access to GTalk, Yahoo, MSN/Live Messenger, AIM/iChat, ICQ, MySpace, Twitter, Facebook, and Jabber. With multitasking and push notifications in iOS 4, IM+ has been transformed from a curiosity into a must-have freebie app.
39. Atomic Web Browser LiteThe lite version of Atomic is missing quite a few features that are found in its paid-for version, including even basic multitasking support and content resumption on reopening the app. However, for times where you need a single-session browser that automatically dumps everything on exit, such as when buying gifts, this is a handy app to have installed.
40. Virtuoso Piano Free 3Virtuoso Piano Free 3 won't turn you into a virtuoso, but it's a perfectly serviceable mini piano. You can amend the number of keys shown on screen, and buttons enable you to rapidly navigate the full keyboard. You get two built-in voices for playback, to which you can add variable levels of sustain.
41. TuneIn RadioDon't bother buying a DAB radio - just install TuneIn Radio instead and plug your device into a set of speakers. TuneIn Radio has a great interface for accessing over 50,000 digital stations; it also has AirPlay support, and you can use it as an alarm clock.
42. 4oD Catch UpTechnically, more like '4oD Catch Up With A Specific Chunk of Channel 4's TV Shows Only' (archives are minimal in the iPhone version); also 4oD Catch Up lacks subtitles and AirPlay support. But it's free, unlimited, and gives you a month to catch up with Channel 4's programming on your device.
43. Jamie's RecipesMore a gateway drug for the tasty treats of Jamie Oliver, this IAP-infused app nonetheless flings ten freebie recipes your way and a few videos. The interface in Jamie's Recipes is lickable, and there's a handy shopping-list feature, for those of you who don't fancy arriving back home after fighting the crowds in the supermarket, only to find you accidentally picked up 500 lemons and forgot the chicken.
44. InstagramTake a photo, smash a filter into it, and upload it. Instagram's service is now used by millions of people to share nuggets of visual loveliness, and the app itself is a pleasure to use, and also to browse during moments when you're not feeling quite so inspired.
45. Google TranslateAssuming you're online, Google Translate is a great app for translating text between 64 different languages; handily, 17 of the most popular also enable you to speak into your device and listen to translations. It's also considerably cheaper and more portable than 63 translation staff.
46. iMotion HDWe say a big PFFT! at CGI. Real animators use stop-motion, until they inevitably go crazy at only being able to craft about three seconds of footage per week. iMotion HD enables you to create such painstaking animations with your device.
The sting in the tail: a £1.49 IAP for export, but if you don't care about that, you can play your creations on your device to your heart's content. There's also the free iMotion Remote to use as a remote controller over Wi-Fi for iMotion HD, to avoid you accidentally moving your 'camera'.
47. TEDTED is brain food. The app provides access to talks by insanely clever people, opening your mind to new and radical ideas. You can also save your favourite talks locally, for even easier access, or ask the app to inspire you, based on your mood and available time.
48. RemoteThe remote for Apple TV is a bit of a joke when you need to do anything more than play or pause. Remote is a free app which provides much better control and the ability to stop yourself going mad when typing things into search fields. It'll also happily use Home Sharing to pull content from computers on your network to your device, or fire said content at your Apple TV using AirPlay.
49. SkyscannerSkyscanner's a great website, which enables you to punch in airports and find out the cheapest way of getting from A to B. The Skyscanner app is the same, but it's on your device and with a spiffy AI. Well worth a download, even if only to check flights for an upcoming holiday.
50. Apple StoreApple fans with a lack of self-control should steer clear of the Apple Store app, which enables you to buy shiny Apple products directly from your device, and also to locate your nearest shrine of tech loveliness (aka Apple Store).
51. BBC iPlayerWatch live TV and browse featured and recent BBC shows in the BBC iPlayer app. There's a favourites section to get easier access to your top shows, and AirPlay support for firing footage at your Apple TV. (This uses the system AirPlay functionality - start playing a show, double-click the Home button, swipe right twice, then choose 'Apple TV' from the AirPlay button.)
52. NetflixBrits might rightly grumble that the Netflix selection leaves a little to be desired, but it's still a very affordable way to get a ton of TV in front of your eyes. The app works much like you'd expect: browse, watch, realise it's three in the morning - again.
53. Camera AwesomeSounding a bit like a rubbish superhero, Camera Awesome is in fact a tool for powering up your device's camera. You get some useful adjustment and composition options, and a load of varied filters are available via IAP.
54. Amazon MobileA great app for anyone regularly suckered by ads but also afflicted with impatience, Amazon Mobile enables you to browse and buy from the mammoth online store with ease. You can also sneakily scan bar-codes in brick-and-mortar stores to see how much cheaper the attached goods would be online.
55. TVCatchupIn all honesty, we're a little surprised TVCatchup still exists, but here it is, in app form. It's not so much TV 'catch-up' as TV 'watch what's on right now', but that's good in itself with support for over 50 channels and AirPlay.
56. SoundCloudSoundCloud is becoming one of those indispensable online services, storing a huge range of songs and audio clips. Although this app is suitable for browsing and playing, you can also use it to record and upload your own sounds.
57. FlipboardIt would be a hard ask to expect the Flipboard experience on the iPhone and iPod touch to match that of the iPad version, but it nonetheless has a good go, transforming your favourite feeds and news sources into a tiny, beautiful digital magazine.
The App Store has so many to-do apps that it's in severe danger of tipping over, due to the sheer weight of digital checkboxes, but Wunderlist is one of the very few that really stands out. The interface is very usable, and the app's ability to seamlessly sync across devices and platforms makes it a great download.
This location-aware sort-of Wikipedia client figures out where you are and fires local knowledge at you. Naturally, Wikihood can be a little scattergun in terms of information, but it's handy for when you're in an unfamiliar place and have a few hours to kill. There are also offline packs available via IAP for regular users.
60. AirPort Utility
Apple's increasingly freeing its iOS devices from any reliance on a Mac or PC, and this utility continues the trend. If you've some shiny white wireless kit at home with an Apple logo, use AirPort Utility to see what your network looks like, muck about with settings, and troubleshoot.
Timers and task managers are usually designed with extreme efficiency, to the point they practically yell NO FUN ALLOWED in your face. 30/30, however, provides a streamlined, tactile interface that happens to look great, is fun to use, and that makes it a breeze to create lists and define timers. It also enables looping for anyone addicted to the Pomodoro Technique.