London, March 17 (IANS) A woman has invented an iPhone application that measures how many calories you burn off while having sex, a media report said Wednesday.

The Bedometer analyses the time and intensity of each session, The Sun reported.

Twentyfive-year-old Livvy Thompson said: 'The results have been amazing. My boyfriend can't get enough of it.'

'Our initial tests show that a vigorous workout for 15 minutes burns almost 200 calories each,' Thompson of North London was quoted as saying.

It is put on the bed and measures activity using the iPhone or iPod Touch's motion sensor and then adds up the calories.

Omaid Hiwaizi of ad agency Chemistry said: 'The Bedometer is the ultimate app as it's fun and functional.'