Who knows where you ran last week? If you're privacy-minded, perhaps just you... and your running app. But our fitness apps often share more information than we realise. The Strava app, and now Polar Flow, have released maps that gave away potentially sensitive military locations.

iOS/Android: When you're the only one paying attention to your workout, it's easy to slip and let your habits drop. Runkeeper aims to fix this by letting you create groups to help you and your friends challenge each other.