As well as offering thousands of free apps, the Android Market, which is Google's offical app store for smartphones and tablet PCs running its Google Android operating system, also offers plenty of paid-for apps that are priced from 62p upwards.

Just like Apple's App store in iTunes, you need to register your credit or debit card with Google to be able to download paid-for apps. Google's purchasing system is now part of Google Wallet, although it was previously known as Google Checkout.

Here's how to purchase a paid-for app in the Android Market.

Step one
Start by opening the Market app on your Google Android device. Now select the app you want to purchase either using the search function at the top left-hand corner of the Market window, or by browsing the categories.

Step two
A paid-for app will have a blue button that says Buy rather than Download. Press the Buy Button and the Google Checkout window will appear. You'll need to enter your location, as well as the card number, expiry date, the three digit security code and your name and address. Once you've entered these details press Save and Continue.

Step three
The card type and last four digits will now be displayed in the far right-hand corner. If you want to pay with this card, simply press OK. The app will begin downloading and your chard will be charged. Alternatively, if you want to pay with a different card, tap the card information and select Add card from the drop down menu. You'll be given the option to add new card details and then save and continue. If you have more than one card registered with Google Wallet you use can use the drop down menu to switch between cards.