Track Addict Pro
Prices: £6.99, iOS (Lite version, free); free, Android (upgrades from 99p)
If you’re happy to buy an external GPS device and OBD port attachment, we’d recommend Track Addict Pro. It works well without these extras, but they boost accuracy. There are circuit, segment and drag modes (more than any other app), plus a variety of pre-loaded tracks, or you can create one. By taking highly accurate data direct from the car and pairing GoPro action cameras, you have a wealth of info to analyse. Imminent updates will include sector splits, too.