Activity Monitor Touch (£1.49, iPhone only):

It offers a similar functionality to Activity Monitor on a desktop Mac computer, but for your iPhone. That might sound a bit dull, and you probably don’t need it unless you’re really into optimising your handset’s efficiency… unless you are having the battery problems that many users report with the iPhone 4S. It seems that the unusual battery drains are almost always software-related, and often occur when a process such as an app gets “stuck”, causing the processor to work continuously and drain the power. So, if your battery drain problems haven’t been solved by updating your iOS 5 to the latest release, Activity Monitor Touch could help you track down which app or other process is causing the problem. Then you can close the process down manually. It also monitors battery usage and offers tips to maximise battery life in general.

Beautiful Clock Radio Spotify Core (£2.49, iPhone or iPad):

Lets you turn your Apple device into a highly customizable clock radio and music player. The clock portion has a gorgeous animated background that alters to reflect the time of day, including sun position or moon phase. You can wake up to any one of 35,000 radio stations, transmitted via the SHOUTcastTM Radio Directory, or to songs from your Spotify playlist. Setting the alarm is quick, intuitive, and easy – just touch the clock-face.

The vscreens app (Free download, Android only):

It is mainly for easily sharing photos from your phone onto a computer or TV screen, but can also play back videos. You can manipulate the on-screen photos using your phone’s touchscreen, too.

Reader for Twitter (£0.63, Android only):

App gives you a little taste of Siri on your non-iPhone. You can have it read your twitter feed as the tweets come in, as well as dictating your own tweets to it for sending out. You’ll need the Text to Speech engine, and voice search, for it to work.

The World in 2012 (Free download, iPhone or iPad only):

It is a major publication from The Economist magazine, now available in app form. The app version contains a selection of the magazine’s carefully analyzed predictions for next year, but has a number of features that the print version doesn’t, such as video footage. If you’re interested in what is likely to be big news next year – the places, people, companies, and things – check out this great free app.

TripAdvisor (Free download, iPhone or iPad only):

It is a newly launched app, but experienced internet users will be aware of the name already, from the popular website of the same name. The website is, in large part, user-created, being a compilation of user reviews of the kinds of establishment you’re likely to want to use when visiting a new city: hotels, restaurants, pubs, tourist attractions, etc. The app offers much the same content as the website, except that you can download all the info on one particular city, then refer to it offline. The big advantage of this is that when going to a foreign country, you can avoid roaming data charges, generally far higher than domestic ones.