Intervention group: Mobile phone based monitoring Patients in the intervention group will be issued with a Piko meter and the T+ software loaded onto their mobile phone. They will be asked to monitor symptoms, medication usage and FEV1 twice a day and submit the readings. The web-record will be available to patient and asthma nurse to aid assessment of control during routine reviews, and to the patients' GP in the event of unscheduled asthma consultations.