Dear Mary | 21 May 2011

Q. May I pass on a tip to readers? Three of my sons are revising for exams at the moment, all in the face of the usual sorts of distractions from social networking sites, cricket and football score alerts, to say nothing of emails pinging into their laptops. I was therefore delighted when they told me that an electronic opportunity to resist these temptations now exists. Two of my sons have installed it into their own MacBooks. Apparently you just go to Google and download ‘self-control app’. This application enables you to set a limit, say two hours, during which all access to time-wasting social networking sites and emails are blocked. You work without interruptions for the self-imposed period at the end of which you are rewarded by the flood of ‘communications’ which have built up in cyberspace. My sons find it most helpful.

— L.G., Fosbury, Wiltshire

A. How very kind of you to alert readers to this useful ‘app’ from which adults could also benefit.