These mobile apps or online games are initially free, but offer players the opportunity to purchases extras, such as lives or special items, through in-app micro-purchases.
It's easy enough for adults to get hooked on games, and 17% of people say they're addicted to at least one, a survey from GoCompare has revealed.
Some of these games are generating an astonishing £1 million a day from in-app purchases - and, all in all, we're spending a whopping £90 million a year.
"Free-to-play mobile and social media games can be a great way to kill some time, but the often simple yet frustrating format can encourage a 'just one more go' mentality," says Matt Sanders of GoCompare Money.
"In-app purchases are usually fairly cheap, but spending £2.99 here and there for extra lives or an item to help you beat that one level that you've been stuck on all week can quickly add up."
In one shocking case in the US, for example, a man spent an eye-watering $1 million playing Game of War.
Even more worryingly, one in ten people say their children play these games regularly - and 8% say they've run up a bill. In some cases, people have been billed thousands of pounds.
"While giving your child a smart phone or tablet to play with may seem innocent enough, but if your card details have been stored on the device, they could quickly rack up a hefty bill by the push of a button," says Sanders.
Parents are recommended to visit the app store and set up a password that has to be used to authorise any spending - before letting their children loose.
So where do people spend the most? Average spend on in-app purchases by region:
1. East Anglia: £24.73
2. Northern Ireland: £21.79
3. West Midlands: £21.73
4. Yorkshire and the Humber: £18.58
5. North West: £14.61
6. London: £13.76
7. East Midlands: £12.25
8. Scotland: £9.41
9. Wales: £9.36
10. North East: £7.07
11. South East: £6.91
12. South West: £5.61
Quirky places to stay with the kids in the UK
Quirky places to stay with the kids in the UK
For a unique camping experience in Britain, champing (church camping) is a magical way to spend the night in a historical building surrounded by the English countryside. The Churches Conservation Trust offers a range of centuries-old churches for you to camp with the kids, such as All Saints Church in Aldwincle, Northamptonshire, which offers medieval simplicity and the chance to get cosy by candlelight before a peaceful night's sleep. From £39 per adult per night and £19 per child.
This bothy, with its huge window and splendid isolation, comes with waiting room-turned-bedroom which was once a Port Appin ferry terminal destined for the scrap heap. With thoughtful crafting, the waiting room is now a cosy bedroom and the bothy a small kitchen - both with incredible views. The Ferry Waiting Room sleeps a family of four in a double bed and set of single bunk beds. It is idyllically located in the Highland wilderness so you can enjoy hikes, climb Ben More or go fishing in the loch. From £140 per night.
Children large and small, and anybody with a playful soul, will be thrilled with this delightful grass-roofed Hobbit house, which invites you to float straight into a magical story book adventure through the picket-fenced cottage garden which blooms with lupins, foxgloves, herbs and wild daisies in spring and summer. At The Shire House, which sleeps six, you'll find a plush, Regency-inspired interior with terracotta floors, wooden beams and a flame-effect log fire. The enchanting bedrooms have cosy cabin beds and the swish bathroom features a golden deep tub and a jam pan sink. From £81 per night.
Tucked away in the foothills of the South Downs National Park is Blackberry Wood, a fantastically wacky camping and glamping site, surrounded by lush woodland. Its impressive Hansel and Gretel-esque treehouse is ideal for little ones eager to live out a real-life fairytale. The house is perched up among the trees and is self-contained with a kitchen, wood-burning stove, outside terrace with chimenea and even a shower in the turret. From £175 per night based on a family of four sharing.
Explore Bath and its beautiful surrounding countryside from this stylish bell tent, which features a wood burner, plus a games room and indoor heated pool for guests. You and your family can get back to nature with all the comforts of a luxury stay in the beautiful home from home. The glamping tent provides a rustic interior, cosy beds for four and a sheepskin rug for a warm atmosphere. From £98 per night.
Nestled in the grounds of the grand Hesleyside Hall Estate amidst the beautiful Northumberland National Park is this small but perfectly formed clutch of glamping huts: three oversized shepherd’s huts and one even larger hut offering a luxurious lodge break for families. The oversized Hersleyside Huts conceal king-sized beds, some with pull-out kids’ beds, as well as bronze bath tubs, plush en-suites, fully furnished kitchens and log burners. Best of all, there are acres upon acres of space in the Estate to explore and, sitting in a Dark Sky Reserve, some pretty fantastic stargazing opportunities when night falls. From £100 per night based on a family of four sharing (minimum two-night stay applies).
This fabulous converted bus in the heart of the Sussex countryside is the stuff of dreams for kids. It features a log burner in the living room, a kitchen and three bedrooms that sleep six. Outside the Big Green Bus, you can make use of a wood-fired hot tub and a fire pit, with plenty of space to explore the wood that surrounds you. The whole family will adore exploring the woodland, enjoying the Big Green Bus' famous chill on the fire put and trips to nearby pubs. From £175 per night.
A unique former radar station, Coastguard Lookout is situated by the seaside in Dungeness and offers uninterrupted views of the sea, just a few steps from the water’s edge. An ideal holiday rental for the family, the property sleeps five and features an open-plan kitchen from where parents can watch the children play outside. Spread over four floors, the modern property offers unparalleled views of the coast and the Kent countryside around. From £201 per night.
Perched at the top of a gently sloping meadow on an organic farm deep in the Dorset countryside, Deerland Safari is a stylish two-bedroom safari tent where you'll find no internet or TV, making it ideal for the whole family to make the most of the great outdoors. Cooking is done on a small gas hob, lighting is provided via candles and torches, and there’s a charcoal brazier on the deck for chilly evenings. The safari tent has one double bedroom and one with bunk beds, plus a separate hut with an eco-loo and hot shower. Kids will love pottering in the fields and watching out for wildlife including deer. From £124 per night (minimum two-night stay applies).
Step out of the ordinary and try a short break with a difference, staying in a converted military helicopter that the kids will love. Those with a sense of adventure will have fun sleeping in this novelty accommodation for four, which comes complete with quirky interiors, a flat screen TV and kitchen with microwave and mini fridge. Grown-ups can bed down in the tail of the 1982 Xray Zulu 676 Helicopter, while little ones have their very own pull-down bunk. Use of the nearby on-site shower block is included and the bright lights of Blackpool are only a short drive away. From £131 per night.
These new glamping pods in the Isle of Wight offer cosy accommodation for up to six people. The Modulogs pods are fully-insulated and kitted out with heaters, comfy sofas which fold out into sofa beds, log burners, dining tables, compact kitchens with all the essentials, two bedrooms, and a separate shower room and toilet. The pods offer WiFi and each has its own decked area with seating, a BBQ area and a log-burning hot tub. From £300 for two nights.