Ownfone, the company that launched the 1stFone credit card-sized mobile device for kids this year, has updated its design to make it even more simple for children to call their parents and other family members.

Where the first 1stFone had words instead of numbers on it face, such as "Mummy", "Daddy" and "Grandad", the new version has a picture of each relevant person's face on a button that dials straight through to a pre-assigned number, making it easier for a young child to know which button to push.

As well as children, the handsets are targeted at older people who might have poor eyesight or those with disabilities - the idea being that it is easier to remember a face than a name.

Ownfone also claims that the 1stFone eliminates the dangers of sending or receiving inappropriate text messages as there is no screen. Nor can they surf the internet.

"It's a fact that more parents than ever before are buying children under the age 11 a mobile phone. Unfortunately it's also a fact that these parents are exposing their children to the risks posed by the traditional handsets currently on the market," said Tom Sunderland, the phone's inventor and founder of Ownfone.

"We launched 1stFone as a solution for parents and added Image Buttons to further simplify the process of making a call to family or friends. This new button design is perfect for younger children as well as those with disabilities."

A 1stFone with Image Buttons starts at £50 (price varies depending on how many buttons are required). It is available on 30-day rolling contracts, pay-as-you-go or with paid in advance bundles for six and 12 months.

As the phone face needs to be printed to order, you can buy one only from myownfone.com.