A new iPhone app aimed at lone travellers and people who work late promises to send an alert to your chosen contact in an emergency.

StaySafe comes in two versions - a free, Lite version and a paid-for full version which costs £1.99 per month - and lets you set up an alert that will be sent to a specific contact if you do not disable it.

The alert contains information about the last known whereabouts of the person who set it up. It is sent via email though the Premium version will also send the alert by SMS if you so wish.

When setting an alert, you can specify the details of what you're doing - for example, working the night shift or going on a blind date - and when you expect this activity to end.

Should you not disable the alert by the time the activity is over, which is done by inputting a PIN code, the alert will be sent. To prevent you forgetting about the alert, your iPhone will vibrate or ring five minutes before the activity's end time. You can also extend the timer if the activity is ongoing.

There is also a panic button feature that allows you to send out immediate alerts should you wish and if you should be forced to cancel the alert by an attacker you can enter a special 'duress' PIN which appears to have cancelled the alert but actually sends it.

Dave Carruthers, Managing Director of One Result said: "StaySafe was developed as a way to turn something many people carry with them all the time – their mobile phone – into a personal guardian that would let their friends and family know immediately if they were in danger even if they were unable to make a call or send a text."

You're limited to just one contact with the free version though the Premium version allows you to enter up to five. It can be downloaded from the App Store.