ChatSim is a new network idea that enables you to use any of the messaging apps on your phone or tablet as much as you like, all for just one yearly fee of £8. It works in countries around the world, and you don't even have to be on Wi-Fi to make use of the unlimited service.

A one-off payment of a further £8 buys the SIM card, which you can slot into any phone or a SIM-enabled tablet - such as an iPad. The card then connects to a local operator, with 250 available in around 150 countries, including the US, UK and Australia.

It currently works with WhatsApp, BBM, Telegram, Facebook Messenger, WeChat, QQi, Line, Hike and Kakao. ChatSim is also working to add others in time.

Any text message or emoji sent through those apps is covered by the yearly fee, no matter the location.

Users can also buy credits to add extra data-hungry services, including photo and video sending and voice calls.

For £8, you can add 2,000 credits to your account, which will cover up to 200 photos, up to 40 videos or up to 80 minutes of voice calls through compatible apps. £20 buys 5,000 credits, and £40 buys 10,000 credits.

As the credits are used to pay for rich data functions, you can therefore get up to 400 minutes of voice calls, 1,000 photos or 200 videos.

You can check out ChatSim on the company's website at