A smartphone with two screens - one of which uses e-ink technology and is "always on" - has been launched.

The Russian company Yota said the phone would go on sale online immediately in Russia, Austria, France, Spain and Germany.

The Android-powered phone promises to extend battery life by transferring web pages and other applications to the e-ink screen.

Experts said it may prove attractive to users fed up with drained batteries.

The phone has one LCD display, similar to those found on other smartphones, and a second e-ink screen which the company says lets users see the information they want without having to wake up the phone.

"The typical user picks up and activates their smartphone more than 150 times a day," said Yota Devices chief executive Vlad Martynov.

"Why? Because users worry that messages or information they need or want are hidden behind their phone's black screen. This is a huge distraction and can impede meaningful interaction with our friends, families and colleagues."