Snooze better with sleep tracker apps

Developers of sleep tracker apps for smartphones say the program can help you to sleep more soundly. But can you really believe their claims?

Say your alarm clock rings in the morning and you wake up ­unrefreshed. Did you go to bed too late? Are you simply a night owl? Would it have been better if the alarm had gone off 10 ­minutes earlier and didn’t ­interrupt your dream?

Developers of sleep tracker apps for smartphones say the ­programs can answer questions like these and help you to sleep more ­soundly.