Cycling is one of the best forms of exercise there is - and can done as part of a daily routine (e.g. going to work/shops/etc.) rather than something that needs time specially allocated. CycleStreets helps people discover practical routes for cycling, away from traffic - which are not always obvious if you're only used to driving. Just enter a start point and finish point, and CycleStreets will give you the best route!
Available for iPhone, Android, or at http://www.cyclestreets.net/ - all free. Over 1 million journeys planned, and featured by the government on its data.gov.uk website.