Geek chic: top beauty apps for men and women THE latest hair and beauty apps promise personal styling in the palm of your hand, but do they deliver? Just when you thought you'd rather lose the fingers of both hands than lose your mobile phone, that cheeky little electronic device in your pocket has just gone and got even more indispensable. The latest apps take all those tricky grooming decisions - from what to do with your hair to what tie to wear for any occasion and how to stop your mascara clumping - out of your hands. Facebook, Twitter and mobile technology are all increasingly seen by brands as an effective way to get their message across, and ultimately, of course, it's all about selling a product. But how effective are these how-to apps for the consumer? To download or to ditch, that is the question. Hands-on Hair LADY Gaga's stylist, Patrick Cameron, is a self-proclaimed long-hair expert. So if you've ever wanted to know how to achieve the perfect Tiffany roll à la Audrey Hepburn, a boho braid, 1960s beehive, classic low chignon or "the halo," he's the man who can. Each app costs £1.49 and you get Cameron talking you through the styling process. There is also a free "top tips" version of the app, which focuses on Hollywood waves, the perfect ponytail and backcombing. A great first step to making every day a good hair day. But these large files need a wi-fi connection to download. Opi THIS is a fun one, letting you "try on" any shade of polish from Opi's collection, from the lime green Who the Shrek are You? to Pompeii Purple - and everything else in between. A virtual hand appears on the screen; change the skin tone to match your own, then scroll through the colours to see which ones look good on you. Then you can search for your nearest salon to get the real thing. Oh, and it's free, which is handy. Lookz - Barry M YOWZER, this is so pink and sparkly, it has teen girl mag written all over it. Which, I suppose, is the point. The content is regularly updated, but on the day I checked there was a worthwhile video tutorial on how to apply liquid eyeliner without ending up looking like Amy Winehouse, and tips on pencilling in eyebrows. The whole thing wasn't exactly user-friendly, however, and there seemed to be rather a lot of content missing. So, while many of the reviews were of the rave variety (accompanied by numerous emoticons to illustrate the fact), there are still one or two technical glitches that need smoothed out. Dolce & Gabbana: Rules for the Modern Gentleman LAUNCHED in collaboration with its newest male fragrance, The One Gentleman, D&G's titular "rules" are written by none other than GQ editor and all-round smoothie Dylan Jones. You'll get etiquette tips along the lines of, "Avoid getting drunk in the company of strangers. They'll be even more embarrassed than you" and "Commit the colour of your love interest's eyes to memory. She will test you on this, and a lot sooner than you think. Essential pieces of kit, according to the rules, include "a well-made, sturdy umbrella," longer socks, to cover that expanse of ankle when you cross your legs, and regularly polished shoes - "Scuffed shoes will ruin even the most dapper ensemble." Fascinating, fun and free. I loved this one. BieberHair LOVE him or hate him, that floppy Justin Bieber barnet is everywhere. But what would it look like on you? Or your Auntie Doris? Or your cat? It's very silly, of course, but quite a giggle. Download a photo of your victim and the app superimposes an image of the boy wonder's locks on top. It costs 69p - a small price to pay for an afternoon's entertainment. Beauty Genius by Marie Claire AS WELL as containing a run-down of all the latest catwalk looks, party faces and wedding make-up, there are easy-to-follow demonstration videos on, for instance, achieving drop-dead gorgeous siren-red lips, applying false lashes and getting the classic blow-dry just right. This is a free app, though some elements carry an additional cost - which seems a little sneaky - but the shopping bag means that you can buy anything you like the look of on the spot, meaning this really is a one-stop beauty shop. L'OrÉal Paris MAYBE you are seeking to achieve that smouldering Eva Longoria look or perhaps Cheryl Cole's girl-next-door gleam. Well now L'Oréal's free app has all the product info with which to do it (though you might be surprised to discover that you still actually look like you at the end of it all). There are how-to videos for applying spray tan, hair dye and eye, face and lip make-up, plus the all-important store-locator. But it's really an elaborate advertisement rather than an effective tool. Ladies, you're definitely worth more than this.