'I love what I do': Justin Fletcher's Mr Tumble shows have won him Baftas, famous fans and an MBE

"I see myself as a bit of a pre-school Mr Bean," says Justin Fletcher, discussing his alter ego, Mr Tumble, a clown who uses sign language for children with speech difficulties on the Bafta-winning TV show Something Special. And if you've never heard of Fletcher, Something Special or Mr Tumble then it's also likely that you haven't reared a young child in recent years. For by dint of hard work, seemingly boundless enthusiasm and a fertile imagination, Fletcher has become the undisputed king of pre-school television, while his wide and varied charitable work has earnt him an MBE.

"Very surreal," says this expert in the surreal (you should see him in a dress). "The Queen gave it to me at Windsor Castle." From under his bearskin hat, one of the Grenadier Guards on duty that day apparently muttered his character's trademark clarion call, 'Mrrrr Tumble!', but Fletcher couldn't see which one "because they were all so poker-faced".

This youthful-looking 43 year old is a one-man industry. He been all over the BBC's pre-school channel, CBeebies, for the best part of 15 years – in Tikkabilla, Higgledy House and the on-going Justin's House (a sort of Crackerjack de nos jours) – and in disguise as a multitude of characters (all his own creations) in Something Special and Gigglebiz, which he calls "a sort of pre-school Fast Show". He's fond of these tags, elsewhere describing the series as a "pre-school Little Britain", as if Little Britain wasn't already just a bit pre-school.

On top of all this, Fletcher has voiced Jake and Doodles in Tweenies, as well as playing Shaun the Sheep and providing a variety of different "baas" in its wordless pre-school spin-off, Timmy Time. And then there are the sell-out arena tours, with adoring audiences of 8,000 parents and children, the DVDs produced by his own production company, Scrumptious House, and his dreams – one day – of making a movie. "It would be a great challenge to bring younger children into the cinema," he says. He has a point; my daughter, now aged seven, wouldn't go near a cinema for the first five years of her life, daunted by the darkness and cavernous space of these 20th-century entertainment arenas.

Anyway, onwards to the current century, and Fletcher has now developed a series of computer apps – the reason that I've been granted this interview. The apps, the first of which – an interactive retelling of Goldilocks and the Three Bears – was launched in May, with others following in ensuing months, have been produced in partnership with Fletcher's long-term collaborator Allan Johnston, a former BBC producer and co-creator of Something Special.

In an editing suite in deepest Soho, Johnston explains the USP of the Justin's World apps, although his voice is largely drowned out, when I come to play back my recording, by Justin's sing-song narration on the app he's playing ("Hay-lo… I'm Justin, and welcome to Justin's World…"). I do manage to pick out one important element for cash-strapped parents, and that is that once the app is bought, there is no enticement to further purchases. It's all there in the headline price. "Do youf know what the average spend on a 'free' app is?" asks Johnston. I don't even own a smartphone, I reply. "About £12," he continues. Goldilocks and the Three Bears currently sells for £2.99 on iTunes.

I ask Johnston what makes Fletcher such a brilliant children's entertainer. "An innate ability to communicate with children," he replies, far too polite to add "obviously". "I do believe you're born with it," he says. "You can't workshop it." Not that the young Fletcher wasn't open to instruction, citing his first commissioning editor at the BBC, Iain Lauchlan, instilling in him "the three c's… clarity, contact and commitment… you can't fool children".

With three awards, Fletcher is the most Bafta-garlanded figure in British children's TV history, although he'd probably defer to a figure he calls "the man" – Brian Cant – the Play School presenter who provided the voice-over for those Sixties classics, Camberwick Green and Trumpton. "He was for me one of the governors of children's television when I was a child," says Fletcher. "I was lucky enough to meet him a couple of years ago at the Children's Baftas and he got a lifetime achievement award."

Fletcher himself was born in Reading, Berkshire, in 1970. His father is the songwriter Guy Fletcher, who penned hits for Elvis Presley, Tom Jones and Joe Cocker – as well as Cliff Richard's 1973 Eurovision entry "Power to All Our Friends" – and now chairs the Performing Rights Society. One of five children, he grew up surrounded by visiting musicians, such as Rick Wakeman and Ron Goodwin, who scored the music for Where Eagles Dare. "He used to play that on the piano," says Fletcher. "I was completely mesmerised.

"Most of my ideas come from film music," he says somewhat surprisingly. "[Erich] Korngold was a really big influence, the swashbuckling Errol Flynn films… The Sea Hawk, Captain Blood and Robin Hood. I just found these scores so invigorating… they would bring my brain alive."

His other, and rather more obvious, influence, is silent comedy. "Chaplin, Keaton, Laurel and Hardy…" he says, adding that he'd also place Kenny Everett within this pantheon (Fletcher's father provided music for The Kenny Everett Video Show). "I really analyse a lot of the moves… the sequences. My first job out of drama school was a play called What a Performance, which was based on a music hall performer called Sid Field, and I was taught by a chap called Jack Trip. He taught me how to do a double-take and do all the falls… the best training I ever had.

"Some people worry that the format is old-fashioned. I disagree with that. Justin's House is pure slapstick for 25 minutes and the laughter… there's nothing better than hearing a child laughing… genuinely laughing." Indeed, one of the first times I remember my daughter chuckling unrestrainedly at a TV show, it was at Gigglebiz, although it was the wordplay in the names of Fletcher's characters she liked best – the likes of reptile keeper Anna Conda, weather presenter Gail Force and dozy newsreader Arthur Sleep.

Drama school for Fletcher was the Guildford School of Acting, where his contemporaries may have dreamed of playing Hamlet or Juliet, or even just jobbing on Casualty, but he aspired to be in the BBC 'Broom Cupboard' – the continuity gig on Children's BBC. "I watched Phillip Schofield when he used to do the Broom Cupboard with Gordon the Gopher, and realised children's telly appealed to me. And when I later met Schofield, he suggested I put a show-reel together."

And with the assistance of his sister, a newsreader at Meridian TV, that's exactly what Fletcher did next, catching the attention of BBC producer Iain Lauchlan – he of the "three c's" mantra – who cast the 22-year-old in Fun Song Factory. Lauchlan would then go on to produce the legendary Tweenies, and a fruitful mentorship was cemented.

In Fun Song Factory, Fletcher played a character called Mr Jolly, which also just happens to be the name of the spiteful clown in Psychoville, the twisted BBC sitcom from the makers of The League of Gentlemen. I wonder if there is a dark side to the clown in Justin Fletcher. Does he ever tire of his allotted role and get snappy with the demands of kids and their parents? Fletcher looks as if such rudeness was genuinely alien to him, but does allow that, "It is tricky when you're filming in public and there are thousands of people and you've got to be quite upbeat all of the time".

My next question makes me feel like I've just dragged something fetid and deeply nasty into the innocent joy of Fletcher's world, which indeed I have. It seems to need addressing, however, because ever since the revelations about a certain white-haired Top of the Pops presenter and tireless fundraiser emerged last autumn, the BBC has become beyond paranoid when it comes to anything to do with children. Had the Jimmy Savile scandal in any way polluted the environment in which Fletcher works? "It's a different era," he says. "I've been on numerous courses over my career… it's so protected. It's such a safe place for children on CBeebies." Allan Johnston, who has worked in children's TV for even longer, agrees. "The safety of the children has always been paramount on CBeebies."

And so we move on to more convivial topics, such as Fletcher's celebrity fans. Johnny Depp is one apparently, as are comedians Simon Pegg, Michael McIntyre and Peter Kay. And Gary Barlow was full of praise when awarding Fletcher a Children's Bafta in 2010, the two keeping in touch since. "A lot of people in the entertainment world have children," says Fletcher, "and you have all these fans that come out of the woodwork." He might even like to work with some of them one day, "on an adult film… but not a dark one".

Fletcher lives in Berkshire, close to his family but alone except for two cats with the very Fletcher-like names of Freckles and Muddles. "I'm a bit of a workaholic, there's no doubt there," he says. "But when I shut down and go home I'm actually a very quiet person. I enjoy nothing more than countryside walks and a bit of fishing." He'd like to have children of his own one day, but "I've got a lot of nieces and nephews and cousins, particularly I've got a little niece called Lara, she's just leaving CBeebies now, up to six and a half, seven, crossing over to… you know." I know. Having left the safety of CBeebies, my seven-year-old is reassuringly embracing Blue Peter at the moment, after a disconcerting fixation on property shows such as Escape to the Country and Four in a Bed.

"You know, it won't last forever," he says when I ask him why he does work so hard. "As an actor or performer or presenter… you do have a shelf-life. I try to reinvent myself all the time… coming up with a new format… that is key to survival. I don't think there's many people in any area that go for longer than 20 years, particularly in children's television."

What would he do if and when that day comes? "I'd probably go into production. In fact, before I ever went into children's television I was very into filmmaking. I used to have a cine-camera and I used to animate and enter all the young filmmakers' competitions. But what I don't want to do is to break away from children's television. I'm not using children as some sort of stepping stone. Some people do – particularly presenters on daytime. I love what I do… that's why I've been there so long."

To watch a clip of Mr Tumble visit www.bbc.co.uk/cbeebies