The Ojoy A1 wearable phone addresses one pain point I have had with such watch phones designed for children: short battery life.

This safety tracker-cum-communication device, one of the first to work on 4G networks, can last for two days without needing another charge.

Most other similar gadgets, many of which work on older 3G networks, last for only a day.

You really do not want to lose connection with your child because the device's battery has run out of juice.

The Ojoy A1's default power- saving mode uses Wi-Fi and cellular base station positioning, which is what most people need as this mode also provides indoor tracking.

For more precise outdoor tracking, parents and device administrators can switch to Global Positioning System (GPS) using the Ojoy smartphone app.

GPS tracking relies on unobstructed line of sight communications with earth-orbiting satellites and drains battery. Even so, the watch phone can last for a full day without needing another charge.

Just like other watch phones designed to ensure the safety of its wearer, the Ojoy A1:

• Needs a SIM card for continuous location tracking and making calls;

• Allows calls only from phone numbers added to its contact list;

• Allows its wearer to send voice messages to listed contacts;

• Keeps the location history map of its wearer for more than a month;

• Must be switched on to enable tracking; and

• Has an SOS button for sending distress alerts.

SOS alerts are sent via SMS to listed family members. They need not download the Ojoy smartphone app to receive such alerts.

But if they want to track the location of or receive recorded voice messages from the watch's wearer, they must use the Ojoy app.

Normal phone calls can also be made from or received on the watch independent of the Ojoy app.

The watch is child-friendly in many ways.

For instance, my nine-year-old daughter needed no help to add contacts, make calls or send messages. She was busy spamming everyone with messages after creating a family group chat in less than a day.

Another nifty tool for worried parents is an eavesdropping feature - similar to what the competitor Oaxis myFirst Fone S2 provides.

The Ojoy A1 is free with Singtel's two-year Mobileshare plan at a promotional price of $9.90 a month. This plan draws mobile data, SMS and talktime allowance from any existing Singtel postpaid plan.

Alternatively, the watch retails for $169 until the end of next month (usual price: $189).

It is bundled with a Singtel $2 prepaid SIM card for free. Users will get free 150 minutes of talktime and 500MB of mobile data every month for 12 months with a minimum top-up of $10 a month for the next 11 months.

I would go for Mobileshare. After 24 months, I would have paid $237.60 for both the watch phone and connectivity. That is not too pricey for some peace of mind.