If "get fitter" was on your list of New Year resolutions, a little something else was probably on that list: "Get a Fitbit".  However, as those devices can vary somewhat significantly in functionality and pricing, which Fitbit should you ultimately choose?

Here's a rundown of many of the firm's flagship Fitbit wearables and what you can expect from each.

Fitbit Charge 3

Fitbit brought out this new iteration in its Charge line only in October 2018, just two years following the Charge 2. Therefore, it seems like an especially good time to buy the Charge 3, with the wealth of up-to-date tech packed into it - and the sweetener is that it's simply a great all-rounder.

You could call this the magnum opus of Fitbits right now. It can track your steps, distance, calorie expenditure, ascended floors and heart rate, and the enhancements over the Charge 2 include a larger display, full waterproofing and week-long battery life - all for $128.95 from Amazon.

Fitbit Versa

While the Charge 3 would be the best choice for most buyers, striking a nice balance between features and price, you might have more specialist needs. For example, if the Apple Watch's smartwatch features have caught your attention, the Fitbit Versa could be a good alternative.

This is Fitbit's entry-level smartwatch - and, compared to its pricier sibling the Ionic, has a more gender-neutral design but lacks built-in GPS. Otherwise, the Versa has much in common with the Iconic, including access to Fitbit Coach and Fitbit Pay. The Versa's Amazon pricing starts at $169.95.

Fitbit Ionic

Before the Versa brought Fitbit's smartwatch journey into the mainstream, the company was making a little bit of history with the Ionic, officially its first ever smartwatch. Buying the Ionic now for $229.95 from Amazon will net you access to the Fitbit app store and Fitbit Pay.

However, a wealth of fitness-tracking tech - including an altimeter, accelerometer and heart rate monitor - is also packed into the Ionic's futuristic casing. This device is also available as the Fitbit Ionic Adidas Edition - though, for $259.95, it largely just adds Adidas branding to the Ionic experience.

Fitbit Ace

If you want your children to grow up into healthy and fit adults, you could certainly do much worse than buy them a Fitbit Ace. Fitbit has carefully crafted it to be child-friendly, with the fitness tracking - including step-tracking - limited to the basics, perhaps to avoid inducing health anxiety in children.

While it's still technically possible to set up a more "adult" Fitbit for your child to use, the Ace's complete applicability to all child privacy laws makes it look like the more responsible choice. However, unlike many Fitbits, it isn't swimproof, so your little ones couldn't enter the pool with it.

Fitbit Alta

If you want an all-round fitness tracker, but your budget wouldn't quite stretch to the Charge 3, your thoughts might turn to the Alta. Its style is highly customizable - you can choose from various straps for it - and it's a sleek little thing for just $87.62 from Amazon.

However, for $128.94 from the same source, you could buy the Alta HR, a significantly improved version with the headline addition of continuous heart rate tracking. Nonetheless, even the HR lacks GPS and isn't waterproof, so it's not obviously suited to avid runners and swimmers.

Fitbit Flex 2

For people whose regular exercise largely consists of swimming, the Flex 2 looks like a great-value fitness tracker. It's inconspicuous, looking largely just like a colored band while 30% smaller than the first Flex, and - obviously importantly - is water-resistant.

The swim-tracking features include being able to automatically monitor pool sessions as well as laps, duration and calorie expenditure. The Flex 2, which comes in black, lavender and magenta, can also monitor other facets of your health and fitness, such as your steps and sleeping, and retails for a starting price of $59 on the Amazon site.