At £99.99, it's the lowest price we can see at the moment, outdoing even Fitbit's own Valentine's Day Sale, where the same tracker costs £109.99.

The waterproof Charge 4, which launched last April, is about as feature-packed as you can get without upgrading to a fully-fledged smartwatch. 

The Charge 4 comes with a built-in GPS, a feature that's usually reserved for Fitbit's more expensive devices, and last July Fitbit further upgraded the Charge 4's firmware with a new Dynamic GPS feature. Dynamic GPS allows the Charge 4 to swap over to your phone's GPS if it's nearby to save battery life.

The Charge 4 also offers Active Zone Minutes, which tracks how long you keep your heart pumping – whatever the exercise – and incentivizes you to maximize effort. It's personalized to your age and resting heart rate, and notifies you when your BPM reaches the Fat Burn, Cardio or Peak zone, so you can push harder and make your workouts more effective.

Other features include an optical heart rate monitor, NFC payment, Cardio Fitness Level, guided breathing, move reminders, and phone notifications (caller ID, texts, calendar, WhatsApp, etc.) to list a few.

You'll also get all the other basics too of course, like step count, distance, calories burned, hourly activity, floors climbed, swim-tracking, and sleep tracking.

See our full review of the Fitbit Charge 4, where it earned 4.5/5 stars. If you need more inspiration, we're also looking at other excellent Valentine's Day gift ideas for gadget lovers here.

You can also see the best Fitbit deals of the month in our dedicated round-up.