Swipe for sex: Love me Tinder, love me true

All dressed up and no one to do? A brave new world of hook-up apps are at the fingertips of anyone with a smartphone and a decent photograph of themselves.

''It is a lot of fun," said Kim Mulholland (not her real name), a media lawyer, "though its quite mercenary - completely biased towards good looks."

Unlike dating sites, which focus on building profiles, Tinder works on the hot-or-not principle - users judge the photographs of fellow Tinderers by swiping right if they like them, or left if they don't.

''It is reminiscent of that 'Pass-Fail' kissing game we played as kids. Boys stand in a line and girls walk past: a pass got a kiss, a fail got passed over," says Mulholland.

Tinder, like most of the mobile hook-up apps, is location-specific - when you load the app, a grid of portraits (ordered in terms of geographical proximity, your nearest Tinder user is posted at the top) unfurls itself across the screen. If you like someone on offer and they like you, too, you get a match and your details are shared. Then it's all systems go as you make a time and place to meet.

It's quite a heady experience - all these available men, effectively coming on to an air-brushed, over-exposed, flattering angle photo of you (but they get the idea, right?).

Launched in September 2012, Tinder already has more than 450million profiles worldwide that are rated every day, and membership is growing by 15% each week.

Tinder is based on a much earlier hook-up app for gay men called Grindr, developed in 2009 by Joel Simkhai, that has been called the sexual equivalent of ordering take-away, or online fashion. It has opened a Pandora's box of hook-up apps that are taking the world by storm.

Blendr

The straight cousin of the legendary Grindr app, it works in a similar way. By using your location, a set of interests and a profile picture, the app allows users to easily hook up with people nearby. It can be used for casual encounters or something more long- lasting. However, as in the real world, it is likely you will have to kiss some frogs before finding your royal match. Available on iStore and Android.

Tinder

The 21st century's version of the bar hook-up, without the hawk-like drink surveillance. Once the app is downloaded finding Mr/Mrs right (or Mr or Mrs right now) is as easy as indicating left or right. Each profile has a picture, first name, age, some Facebook preferences and a short tag bio. Once mutual ''liking" occurs, users will be able to chat within the app and love (or something like it) will have the chance to blossom. Available on iStore and Android.

Scruff

Gay, bisexual and bi-curious men looking to expedite the process of finding a partner are blessed with an abundance of them when using Scruff. Users can privately exchange photos and flirt or ''woof" at each other using the app before deciding to meet. The app claims to have more than fivemillion users worldwide who cater to a wide variety of tastes. Available on iStore, Android and Windows Phone.

Manhunt

The name says it all. Another app for gay, bisexual and bi-curious men. It works like other mobile dating apps using your location to help facilitate trysts. Be warned - it is edgier than many other mobile dating apps. Available on iStore and Android.

Gaydar

The Facebook of online dating. The app allows users to create profiles for others to view with info such as your interests, photo and videos. Should you have travel plans, the app allows you to tell people in that particular country that you will be in town and what language you use to communicate. Available on iStore and Android.