[Digital Today reporter Choi Jae-won (최재원)] As more parents worry about their children's indiscriminate smartphone use, kids' phones that offer only essential functions such as calls and texts are drawing attention. Products that block web browsers and social media, or allow parents to directly control app use, are being released one after another.

On Nov. 7 local time, IT outlet TechCrunch reported that in the United States, companies such as Bark, Gabb and Pinwheel are rolling out phones focused on children's online safety.

The devices have touchscreens and cameras similar to regular smartphones, but are characterised by restricted software functions. Parents can use dedicated apps to manage contacts, location and usage time, and some products detect cyberbullying or inappropriate content and issue warnings.

Bark Phone applies its own monitoring technology to Samsung Galaxy devices. It allows calls and texts only with approved contacts, and alerts parents when it detects warning signs in messages and photos. Web searches and app use can also be allowed depending on a child's stage of development. The handset costs $240, and service plans start at $29 a month.

Gabb focused on blocking access rather than monitoring risky content. It removes social media, web browsers and app stores, and provides only selected functions such as calls, texts and a camera. The handset costs $159.99, and monthly service starts at $24.99.

Pinwheel lets parents approve apps and contacts and restrict functions to match school classes or homework time. Handsets start at $119, and its guardian management service starts at $14.99 a month, excluding service fees.

Teracube's Thrive uses a customised Android operating system. It supports app-installation approval, web filtering and screen-time limits, while offering relatively broader functions of a general smartphone.

Screenless home phones have also emerged. Ooma MyPhone and Tin Can focus on calls with approved contacts, while Waffle is taking pre-orders for Waffle Home for use at home and the portable Waffle Go. Canadian telecoms company TextNow also released Yellow!, which restricts social media and app stores.

In the kids' phone market, a key differentiator is emerging not in how many smartphone features a device offers, but in which functions parents can control and allow in stages.