We're used to seeing celebrities preened to perfection, with glamorous gowns, voluminous blow-dries and, of course, immaculate makeup.

But a new app reveals what some of the best known stars in showbiz might look like without the help of their glam squad.

The app, called MakeApp, digitally 'removes' all trace of cosmetics from photographs, and it has been road-tested on some of the most flawless faces on the red carpet.

Celebrities given a digital make-under by the app include the Duchess of Cambridge, Cheryl Cole, Victoria Beckham and even Prime Minister Theresa May.

Scroll down for a glimpse at what the app suggests the stars might look like without the slap...

‹ Slide me › A royal beauty! The Duchess of Cambridge still looks youthful without a scrap of makeup, after it was digitally 'removed' using the MakeApp (slide left to reveal Kate with no makeup)

‹ Slide me › Made under! Proving she's a natural beauty, X Factor judge and Girls Aloud star Cheryl looks very fresh faced without her slap (slide left to reveal Cheryl with no makeup)

After downloading the app, users can let MakeApp wipe away their own carefully applied 'face' on photos - or for a more enjoyable experience, use it to add cosmetics instead with a variety of looks - similar to Instagram filters.

It works with both videos and pictures, and allows users to lighten the skin, minimise redness, or tone down harsh lipstick.

But while the app has caused something of a stir online, it has not been met with unanimous approval, with Revelist calling it 'a subtler form of shaming'.

The lifestyle site hit out at the makers of the app, calling them 'beauty-hating trolls', writing: 'If a woman steps out with makeup on her face, it's because that's the image that she wants to convey that day.

'It's not up to us, or up to some creep with an iPhone, to determine what she "really" looks like underneath her makeup. If a woman is wearing makeup, it's presumably because she WANTS to, and robbing her of that right is totally unfair.'

‹ Slide me › Stripped back! Victoria Beckham is known for being polished to perfection, but appears makeup free thanks to the new app (slide left to reveal Victoria with no makeup)

‹ Slide me › Great British makeup off! 2016 winner Candice Brown looked completely different without makeup (slide left to reveal Candice with no makeup)

‹ Slide me › May-dover! The Prime Minister is usually perfectly preened to face the cameras (slide left to reveal the PM with no makeup)

‹ Slide me › Transformed! Glamorous stars like Nigella Lawson were given a make under with the app (slide left to reveal Nigella with no makeup)

‹ Slide me › New look! Celebrities like Kylie Minogue stil looked stylish without their makeup (slide left to reveal Kylie with no makeup)

‹ Slide me › Someone like you! Superstar singer Adele still looks remarkably fresh faced without her makeup on (slide left to reveal Adele with no makeup)

‹ Slide me › Strike a pose! Even world-renowned models like Rosie Huntington-Whitely have been given a make under by makers of the new app, which can also 'lighten' skin and reduce redness (slide left to see the supermodel au naturel)

‹ Slide me › Strictly slap-free! ITV host Tess Daly is used to being dolled up in the ballroom, but is pictured here bare faced thanks to the app (slide left to see Tess makeup-free)

‹ Slide me › Stripped back diva! Pop legend Mariah Carey is seen here without her famous long lashes and glossy lips - so does she look better before or after? (swipe left to reveal Mariah with no makeup)

‹ Slide me › R.I.P. to her makeup! Crooner Rita Ora proves she's a natural beauty in her pictures, still looking youthful and fresh-faced without the slap (swipe left to see Rita with no makeup)

‹ Slide me › Holden the makeup back! The Britain's Got Talent judge is known for her less is more fashion sense, which was applied to her makeup style through the app (swipe left to see Amanda makeup free)

‹ Slide me › New look? Gwyneth Paltrow has her own organic makeup range, but appears makeup free in the pictures (swipe left to see the star with no makeup)

‹ Slide me › Still got it! Helen Mirren, 72, proves she's just as glamorous without makeup than she is with a face full of cosmetics (swipe left to see the actress without makeup)

‹ Slide me › Fresh faced! She's used to donning extravagant period costumes in her role as Queen Victoria, but Jenna Coleman looked just as stylish without any makeup (swipe left to reveal)

‹ Slide me › Regal! Claire Foy is best known for playing the Queen, but looks just as good off camera with no makeup on (swipe left to see The Crown star without makeup)

‹ Slide me › Off duty! Katherine Jenkins can be seen with heavy makeup for a TV appearance, but looks fresh faced thanks to the app (slide left to reveal)

‹ Slide me › Like magic! Harry Potter author J.K. Rowling, 52, looks youthful after her transformation with the Makeapp (slide left to reveal)

‹ Slide me › Dancing queen! Strictly Come Dancing judge Shirley Ballas still looks just as glamorous without her makeup (swipe left to reveal)

‹ Slide me › Au natural! Funnywoman Dawn French is also included in the list of celebrities who have been given a make-under - and still looks far younger than her 60 years (slide left to reveal)

‹ Slide me › Spellbinding! Emma Watson is known for her stylish red carpet appearances, and the Harry Potter star is rarely seen without makeup (swipe left to reveal the star au naturel)

‹ Slide me › Made under! Strictly host Claudia Winkelman is known for her love of heavy eyeliner and bright lipstick - and she looks completely different without her makeup (slide left to reveal)

‹ Slide me › Looking lovely! Joanna Lumley, 71, still looks youthful in her made under pictures - despite the app digitally removing her eyeshadow and lipstick (slide left to reveal)

‹ Slide me › Bare faced! Legendary actress Joan Collins still looks like her glamorous self without her trademark makeup after the app removed her lippy (slide left to reveal Ms Collins makeup free)

‹ Slide me › Before and after! Titanic star Kate Winslet is also among the celebrities who had a make-under - although traces of lipstick are still visible (slide left to reveal)

‹ Slide me › Naturally gorgeous! Scarlet Johansson proves she's still one of Hollywood's most desirable women without her makeup (slide left to reveal Scarlet au naturel)

‹ Slide me › Camera ready! Conservative MP Andrea Leadsom doesn't look hugely different without makeup according to the app (slide left to reveal)

‹ Slide me › Model behaviour! Supermodel Jerry Hall is usually preened to perfection, but as the app shows, she's still a natural beauty (slide left to see Jerry with no makeup)

‹ Slide me › Off duty! Angelina Jolie shows off her natural beauty in the pictures - with the actress and humanitarian looking just as stunning without the slap (slide left to reveal)