Following are some free iPhone apps that I recommend. They are not necessarily the apps that I use most often, but each is impressive for a particular reason. If you're reading this page on your iPhone, you can tap on an app's icon to go to straight to the app in the App Store.
If you're out shopping and you wonder how much a particular item costs online, use this app to scan the barcode of the item with the iPhone's camera, and it will check online prices from many internet retailers. It can also scan QR codes (see below) that are cropping up all over the place. There are other apps that perform a similar function, such as RedLaser, but this one seems to be the fastest and to give the best results.
Viber allows you to make free international phone calls between smartphones via voice over IP instead of a conventional chargeable phone call. Calls are made between mobile numbers, unlike Skype which requires the called party to have a user ID known to the caller. The app also allows free text messages between different operating systems, i.e. iOS, Android and Blackberry. You can even geo-tag your text messages, so instead of describing where you are, you can choose to include your current location on the text message.
This app is very useful if you're meeting up with friends and want to find each other on a map. It puts an end to phoning each other and describing where you are when you can't find each other or are lost. You can invite a friend, or group of friends, to share locations with each other until a specific time, for example an hour after your planned time to meet. This is something lacking in other similar apps and is very useful for friends who want to share their locations only for a specific event without being tracked at other times.
You can bank with any bank, not only Barclays. If you need to pay someone money and only have their mobile number, you can send them money using this app. If the payee is not already registered for Pingit, they'll receive a text message telling them how to associate their sort code and account number with their mobile number. Then your payment will go straight into their bank account (at any bank), as will any future payments that other people send them. Payments take a few seconds to be credited to the payee's account and appear on bank statements showing only the payer's and payee's mobile numbers.
If you have Sky+ at home, this app is an absolute must. You can remotely instruct your Sky+ box to record programmes, which is very useful if you're out and forgot to record something. There's a full electronic programme guide in this app, which in landscape mode is actually more user-friendly than the EPG built into Sky boxes. When you use the app to record a programme, Sky will send a signal to your Sky+ box via satellite; you don't need your Sky+ box to be plugged into a phone line.
This is an offline RSS reader. Every night while your iPhone is charging, you can download 1,000 news articles from various news services, such as newspapers and other news web sites, and then read the interesting ones offline on your way to work when your data connection may be slow or non-existent, for example on the Tube. You need to set up an account with Google Reader where you add RSS feeds from your chosen news sources. Byline will then synchronise with your Google Reader account and cache entire web pages of every news article so you can read them offline.
This is the app that used to cost £5, but is now free; they still charge £5 but only if you want to get rid of the adverts. It remembers all your frequent stations and routes, gives you live train running information and has a useful "Get me home" button that will find the optimal trains to get you home from your current location. It can also alert you in advance if your usual train is going to be late or cancelled. This is a must-have app for a commuter who uses mainline trains.
Similar to the National Rail app, Deutsche Bahn provides an app that covers the whole of Europe. You can look up train times to get from one station to another including changes, and the app can find your nearest station as well as save your favourite stations. However, the concept of trains running late is not something the Germans are familiar with, so they unfortunately don't include live train running information in this app.
You can watch BBC News 24 live using this app. The picture quality is amazing, provided you use a wireless connection rather than 3G data. It doesn't work outside the UK because it's funded by the BBC licence fee and the BBC checks that you have a UK IP address. It may work on 3G data outside the UK using a UK SIM card because you would still be seen as coming from a UK IP address, but the data roaming charges could be prohibitively expensive.
This is the international version of the BBC News app, which gives you live BBC World Service radio instead of BBC News 24 television. You'll need to register for an iTunes account outside the UK in order to install it. Once installed, it works inside and outside the UK. To register for an iTunes account in different country from your own (where you don't have a credit card registered to an address in that country), sign out of iTunes, try to buy any free app, create a new iTunes account, choose the desired country, and then choose the option stating that you have no credit card. You will need to register using a different e-mail address from your existing iTunes account.
This app is provided by a leading French speed trap alerting company, France being a country riddled with manned speed traps. Wikango as a company sells a variety of speed trap alerting equipment and services, but they inexplicably provide this app for free using live data contributed in real time by their users. The live data alerts you to manned speed traps and fixed cameras in countries such as France and Belgium, avoiding hefty on-the-spot fines. Even if you don't have a live mobile data connection (because of high data roaming charges), you can still download the data before your journey using a wireless network. You'll need to register for an iTunes account in France or Belgium to install this. To do this, sign out of iTunes, try to buy any free app, create a new iTunes account, choose France or Belgium, and then choose the option stating that you have no credit card. You will need to register using a different e-mail address from your existing iTunes account.
Enter a UK number plate and this app will tell you the vehicle it relates to, including the date of registration, exact model, engine size and fuel type. This is most useful for personalised plates, either to see the true age of a car or to look up what car your desired personalised plate is registered on. The app is free to use, but its objective is to sell chargeable services such as valuations and mileage checks to buyers of secondhand cars.
This app gives you live arrivals and departure information for flights without the need to find the relevant airport or airline's app or web site. It even displays the live progress of a flight on a map as well as an abundance of other flight-related data. This is a must-have app for any frequent flyer, although not all airlines or regions are fully supported.
This app displays real-time positions and headings of commercial aircraft on a map including flight numbers. It only supports airlines whose aircraft broadcast their positions. Although it's not of great practical benefit, it's nevertheless interesting if you're in the garden and are curious to know what the plane is flying above you. If you know someone who's on a particular flight, it can also be fun to see exactly where they are. There is also a paid version of the app which gives more detailed data.
Calls to 0800 numbers are chargeable (often at premium rates) from mobiles, despite previously being free on Orange and T-Mobile until a few years ago. This is a real nuisance if you break down for example. When you call an 0800 number, your mobile network receives revenue from the called party to pay for the call, so it's particularly absurd that the mobile networks all started charging for 0800 numbers. This app exploits this principle in that when you use it to dial an 0800 number, your phone dials a standard London 020 number out of your inclusive minutes, and the operators of this app forward your call on to the called 0800 number at no charge to you, made possible because they, and not your mobile network, receive the revenue from the called party. The result is that your mobile network loses out because of its greedy policy.
This is the iPhone version of the Skype software that you may have already on your PC. You can remain logged in simultaneously on your PC and your iPhone. It's very useful when you're roaming as you can use it to make free or cheap phone calls when you have access to a wireless network such as in a hotel. Beware that it uses your battery more than other apps, so be sure to close it when you you don't need it. To close an app properly, you need to press the home button twice, and press on the app you want to close until the minus sign appears. Then press the minus sign to close the app. If you don't do this, an app may continue to run in the background.
If you find your 3G data connection to be much slower than the advertised 7.2Mbps, you're not alone. Use this app to test the bandwidth of your 3G data or also of a wireless network. Perhaps complain to your mobile network if your 3G data speed is slower than dial-up used to be (i.e. 56kbps or 0.056Mbps). If you're in a moving vehicle, then do not expect the speed to be as high as when you're stationary, as this is a known limitation of 3G.
There are lots of speedometer apps that use the iPhone's GPS receiver, but this is one of the easiest to read. GPS is usually more accurate than cars' speedometers which tend to over-read depending on the manufacturer, so this can be a useful way of testing your car's accuracy. For example, it can be useful to know that when your car tells you you're driving at 70mph, you might actually be doing only 65mph. It can also be interesting on fast trains like Eurostar to see when you've reached top speed.
There are lots of apps to locate Boris bikes, but most of them don't show you simultaneously on a map how many bikes are available from multiple neighbouring docking stations. With the other apps, you have to tap on each location to see how many are available, which is fiddly and cumbersome. This app on the other hand shows all visible stations' capacities by the size of red blobs and the availability by the depth of colour of the red blobs, which instantly gives you a graphical indication of how many bikes are available in your area.
This app is not usually free, but the price sometimes drops to zero for promotional periods of around a week; you can see the price history here. The app performs similar functions to iMessage, allowing you to send text messages without using SMS, but it can send to Android and Blackberry phones; when sending texts to other iPhone users, iMessage remains preferable using the usual Messages app.
You may have seen QR codes cropping up everywhere. They are intended as a fast way to enter data into a mobile phone, for example a web link or a business card, without having to type the data manually. Lots of other apps can read QR codes, but this one is the best I've found with the ability to read more types of data. There's also a chargeable version of the app without adverts and with the ability to create QR codes. The app's developer also has a QR code generator on his web site. Google Shopper and RedLaser can both read QR codes but not as well as this app. If you're not reading this page on your iPhone, then using your iPhone you can scan the following QR code with any QR-compatible app to open this page on your iPhone: