Fidget Spinners are the world's latest toy crazy. If you are new to the party, they are small normally plastic contraptions set on ball bearings, which spin between your fingers.

They've been a hit with both adults who are taken to fidgeting (hence the name) and kids on playgrounds trying to pull off high-speed spinning tricks and trading the lo-fi gadgets like the Pogs and Pokemon cards.

It's unclear how these toys have become such a hit. Unlike Pogs and Pokemon cards, they haven't been backed by TV shows or slick marketing campaigns.

Origins

The toy was actually invented in the mid-90's - 20 years before they came to prominence.

It was dreamed up by Canadian inventor Catherine Hettinger. She recently told The Guardian that during "one horrible summer" when she was suffering from myasthenia gravis, a neuromuscular disease which makes sufferers weak, she invented the initial design.

She was trying to entertain her young daughter who she was looking after. "I couldn’t pick up her toys or play with her much at all, so I started throwing things together with newspaper and tape then other stuff ... It wasn’t really even prototyping, it was some semblance of something, she’d start playing with it in a different way, I’d repurpose it," she reflected.

After bringing her spinners to trade shows and selling a few thousand units she patented her design in 1997.

When a potential deal with international toy giant Hasbro fell through in 2005 she was unable to afford the $400 renewal fee to keep the patent.

So now in 2017 when then craze has gone global she finds herself left out in the cold.

"Several people have asked me: ‘Aren’t you really mad?’ But for me I’m just pleased that something I designed is something that people understand and really works for them," she told the UK publication.

Going global

It's hard to pinpoint the source of the upsurge in interest in these toys.

A look at the history of Google searches for the phrase 'fidget spinner' shows almost no activity until February of this year, when they began to rocket.

While the geographical spread shows that most searches are coming from English-speaking countries and Scandinavia.

The first signs of the craze taking off are listings on Etsy - the platform used by makers of niche goods and crafts to sell their wares - where they gained popularity as de-stressing devices.

Here's an example of an 8-month-old review of some fidget spinners when their popularity was beginning to bubble.

The toys soon started to spread through social media. Many sellers are 3D printing the easy to manufacture design.

Sellout

Some schools across the UK at already banning spinners because they are causing distractions during lessons.

Fidget Spinner tricks and hacks have become their own YouTube sub-genre.

If you are looking to get your hands on one it might be tricky. A number of Irish toy retailers have reported that they are sold out and struggling to secure more - so some patience might be needed.