Note

 
All application names & icons link to their page at AppShopper.com, a brilliant free app directory service that is much easier to browse than the iTunes AppStore.

You can also create an (anonymous) account there, which enables you to automatically keep track of the apps you want or own and get informed about price changes and updates. Saved me lots of money already!

They also have helpful rankings of all categories and consolidated lists of what's new or on discount. Check it out!

All links will open in a new window or tab.

Essential Applications

"Essential" is probably a bit exaggerated (hey, that's me!) but these apps must be on my iPhone or I wouldn't use it and could just as well go back to my old Sony-Ericsson...
Stanza has been driving the digital book revolution with a reading interface that is unrivaled in its clarity and ease of use. You might initially not believe it, but it is not only possible to read books on an iPhone, it is a pleasure! Text can be resized on the fly, and automatic bookmarking lets you always come back to where you left, even when you're (like me) reading five books at once. You can purchase popular new books from a selection of over 50,000 contemporary titles (directly from within the app, downloaded in seconds), or choose from an additional 50,000 free classics, magazines and recent original works available from many sources, including any texts from your own computer. Free! If you don't have this on your iPhone, you don't deserve one.
The Guardian app is even better than the real newspaper (my favourite in the UK). With a highly personalisable access to the world's most comprehensive topic-based news engine, you can stay effortlessly and elegantly informed on the subjects that matter to you. Full offline browsing of the latest stories, galleries and audio news. The best thing is that every article is tagged with keywords and interlinked with related news. This app alone is worth having an iPhone. Really!
Evernote turns the iPhone into an extension of your brain. From notes to ideas to snapshots to recordings, put it all into Evernote and it gets instantly synchronised with your desktop. If you make photos of text (e.g. business cards), the Evernote server even does an Optical Character Recognition, so the text in the picture (!) becomes searchable. This is one of those applications the iPhone was made for. Incredibly, Evernote is still free - at least the basic service, which is enough for most people. You owe it to yourself to check out this application, both on your phone and your desktop. One of the most useful things ever!
ReaddleDocs is a revolutionary document viewer that can catch documents from any source: Windows, Mac or Linux computers, web sites, email attachments, iDisk, Dropbox and other online file storages. All files are saved locally so you can read them anytime, anywhere! ReaddleDocs combines a network file server, online storage client, web browser, file manager and robust document viewer all in single application. Absolutely essential when you get that the iPhone is not just a phone. This app is the perfect all-rounder for all kinds of documents; for PDFs I also recommend the next one.
GoodReader is an advanced PDF viewer, way ahead of any competition. The handling and reading even of huge files (100MB) is superb and the PDF Reflow feature extracts pure text from PDF files and automatically wraps words, so all of the text fits to the screen perfectly without you having to scroll horizontally or zoom in and out. Files can come from your computer, the internet or email attachments. It also integrates with MobileMe iDisk, box.net, MyDisk, Google Docs and Dropbox. Fantastic! I use it to read books and magazines (the Rainbow Bridge!) and to always have my own publications & designs with me. (Almost everything these days comes as PDFs.)
AroundMe lets you quickly find out information about your surroundings. It quickly identifies your position and allows you to choose the nearest Bank, Bar, Gas Station, Hospital, Hotel, Movie Theatre, Restaurant, Supermarket, Theatre, Taxi Service, etc. AroundMe shows you a complete list of all the businesses in the category you have tapped on along with the distance from where you are. For every listing you can choose to see its location on a Map, view the route from where you are, add the information to your contact list or even email the information to a friend. The Nearby listing allows you to find information using Wikipedia about what is around you. Free, so if you don't download this, you're just being stupid!
SoundHound (formerly "Midomi") is one of those apps that are just unbelievable. If you hear a song anywhere (e.g. in a café) and want to know what it is, you just let this application listen to it for a moment, which will than compare the recorded sound file with an online database and give you the song title within seconds. You can also speak an artist's name, song title or even hum the melody and you'll get a result. Not only that, but you can then listen to the original song, watch the video, read all about the artists or download the whole album straight from the iTunes music store. This is just crazy!
Movies by Flixster is the best movie app for the iPhone to view the top box office leaders, find out all about upcoming movies and new DVD releases and watch their trailers. You can then search for cinemas around you and download the showtimes. Movies also links to reviews at Rotten Tomatos and even integrates with Yelp to find restaurants near the cinema you want to go to. And it's free!
Measures is a unit and currency converter with a huge database of almost 1000 units in 38 categories. Because it also has normal calculator functions, it has replaced the iPhone's built-in application for me. The great thing is that you always see both units at the same time, so while you're (e.g.) calculating prices, you can see them in two currencies at every step. Very easy handling and many customisation options. Indispensable!
2Do is a stunning (Best User Interface 2009) ToDo List with Push notification and iCal synchronisation. ToodleDo sync is supposedly coming soon, as well as integration with other services. I had a much more expensive ToDo app before (plus an even more expensive Mac companion application), but switched to 2Do (despite iCal being a bit dull) because it's so pretty and fun on the iPhone that I actually want to to do to do lists! (O.k., too many to dos here...)
Dictionary is an intuitive, consistent, talking (high quality text-to-speech), hyperlinked and integrated English illustrated Dictionary and Thesaurus, Spell checker, Vocabulary builder and Wikipedia browser. There's even a Rhyming dictionary. Optional Translation of words being looked up to Spanish, Italian, French, German and Japanese (translation uses Google translate and requires an internet connection, the normal Dictionary does not). There is a multitude of dictionaries in the AppStore of varying quality and cost. This one beats them all and has replaced four other apps I previously had in one go. Simply the best!
Weather Pro, the app from Europe’s weather specialists MeteoGroup, features weather reports and high-quality hourly and 7-day forecasts for over 2.000.000 locations worldwide. It also supports weather radar for the UK, USA, The Netherlands, Germany, Belgium, France, Scandinavia, Spain and Switzerland as well as animated satellite pictures for Europe, America, Africa and Asia. Not everyone will necessarily need this, but it's a very polished app that has come in handy a few times already.
MagicHour (formerly VelaClock) is a world clock that can quickly display the time of sunrise, sunset, three kinds of twilight (civil, nautical, astronomical) for dawn and dusk, moonrise, moonset, duration of daylight, current phase of moon, date and times for the next four moon phases, countdown to the next sunrise or sunset and next moonrise or moonset, and more.
PhotoForge can be used for image manipulation, retouching, effects, and color correction, as well as a painter’s tool. It is a photographer’s tool that allows you to put together an image, combining filters, brushes, and effects, which can be layered to produce even more dynamic results. If you buy just one photo editing application, this is the one! If you are a bit more professional or playful, also consider the next.
Photo fx is the definitive set of digital optical filters for the iPhone. Simulations of many popular award-winning Tiffen glass filters, optical lab processes and photographic effects (67 exciting filters, containing 780 presets, organised in 9 different groups) will help you create stunning images, whether you are an amateur or professional photographer. Definitely the most comprehensive, feature rich photo app available. Photoshop in your pocket, basically!
Skype makes it possible call and instant-message anyone else on Skype for free. You can also call landlines and mobiles and send SMS anywhere in the world, at relatively cheap rates. Skype is free to download and as easy to use as the desktop version. It does work on the 3G network now, but ideally you should only make calls while you're connected to a WiFi network.
Facebook for iPhone makes it easy to stay connected and share information with Facebook friends while on the go. Obviously you'll only need this if you are on Facebook, but if you're not, you're probably a technophobe and not reading this page anyway. With Facebook for iPhone you can start a chat, check your friends' latest photos and status updates, or upload your own updates and images. Supports Push notifications. Free, of course.
Tweetie 2 is the 2009 Apple Design Award Winner! The Twitter client that redefined Twitter clients is back, and it's even better. Rewritten from the ground up with a fast and powerful new core, it offers the most polished mobile Twitter experience around. If you think Twitter is a stupid waste of time, I can totally understand, but like any other tool it's usefulness depends on your intelligence & imagination. I use it for technical support stuff and news, not to announce that I'm going to the loo...
UltraTimer is an easy and convenient way of timing any activity or series of activities. You can set a single timer or multiple timers, each including series of count-down intervals that run back-to-back. Each interval can be customized to play a different alarm sound from the included library, as well as change the background color for visual feedback. Use it for exercise, workouts, cooking, time management or anything else you can think of. I use it as a meditation timer with several stages.
Documents To Go lets you EDIT, create and view Microsoft Word documents and Excel spreadsheets. You can also view PowerPoint, Apple iWork and other files. Nobody should have to use Microsoft Office, but reality is sadly different. So, if you are one of the unlucky ones, at least this app makes your Office portable. A free desktop app (Win & Mac) enables proper non-destructive two-way file synchronisation via WiFi. There's also a premium version with PowerPoint editing and Outlook integration.