Apple Watch will work with a bunch of built-in apps developed by Apple, some of which have yet to be unveiled.

One of them, which everybody has probably heard about, is the Health app, an easy‑to‑read dashboard that displays all your health and fitness data on the iPhone. Another is the Apple Watch app. It appeared on iPhones weeks ago as part of the iOS 8.2 update and is meant to be an Apple Watch companion app, but for now, it's more like a placeholder.

Apart from the Health app and Apple Watch app, there are two apps you should know about: Activity and Workout. The former app specifically monitors your movements, while the latter app tracks dedicated workouts. They use onboard sensors to measure your movement and heart rate, and even your GPS location with some help from your iPhone.

In an attempt to clear up the confusion surrounding Apple Watch, Pocket-lint has detailed everything you need to know about the Activity app and Workout app, including how they work and when they're expected to release.

Let's address one thing first: Apple Watch is Apple's upcoming first entry into the wearable biz.

It'll be available in multiple territories, including the UK and US, from 24 April. Apple will also offer the opportunity to pre-order Apple Watch from 10 April on Apple.com. You can get Apple Watch in many different models, sizes, and materials. The models are called Watch, Watch Sport, and Watch Edition.

Each model comes in two different case sizes: 38mm and 42mm in height, both of which can be set up to work on your left or right wrist. You must first decide which model you want, then choose your case size and material, and once that's done, you can select from a wide variety of straps.

The cost of Apple Watch varies dramatically, depending on the model and strap you selected. Pricing starts at £299 for the 38mm Apple Watch Sport, for instance, and extends to £13,500 for the 38mm Apple Watch Edition in 18ct gold.

You can learn more about pricing here.

Developer Hamza SoodScreen Shot 2015-04-01 at 11.07.15 AM

When you get your Apple Watch and pair it with an iPhone running iOS 8.2, it looks like a new Activity app will appear, according to several reports, including iMore and 9to5Mac. The app, which was previously known to exist, even though Apple has not shared details about it, won't show up on your iPhone until after you've paired it to Apple Watch.

Developer Hamza Sood uncovered details about the app while digging through a public build of iOS 8.2. He said it will only appear on your iPhone's Home Screen after pairing, and once you're done setting up Activity features on the Apple Watch, it will unlock on the iPhone, meaning it's useless without Apple Watch (just like the Watch companion app).

How it works

The Activity app is designed to provide a comprehensive overview of your daily activity and workout history. You'll see a main History tab, for instance, that allows you to view your Activity rings.

Each ring - called Move, Exercise, and Stand - represents the amount of walking, exercise, and standing you've done over the course of a day, month, or a year. A second tab, called Achievements, displays all the achievements you can try to beat in order to reach a personal best or milestone. There are reportedly about a dozen achievements to start.

Keep in mind that our muscles atrophy without motion, and so Apple Watch's Activity app is meant to make you more aware about how often or how little you're moving over a period of time. The Stand ring tracks whenever you stand up, for instance, while the Activity app actually reminds you to stand. In other words: it encourages good habits.

The Move ring monitors how often you go from standing to walking as well as how many active calories you've burned during the day. You can also set a goal, and the Activity app will even suggest new goals over time based on your movement history. It'll therefore, once again, encourage you to reach new goals.

The Exercise ring shows how much brisk activity you've engaged in, such as a fast-paced walk or a jog, and the Activity app gives you a 30-minute goal. Over time, it'll also require greater intensity. The more you move and accomplish these standing, moving, and exercise goals set by Activity, the more each ring in the app gets filled.

The idea is that Activity will monitor and encourage movement. If you fill an Activity ring, you've accomplished all your movement goals for the day. You'll also see a weekly summary in Apple Watch and a complete history in the Activity app on the iPhone. Leaked screenshots show the iPhone app displays your activity over time with achievements attainted.

It also manages sharing activity and workout data with the Health app, so third-party developers can access your data with permission. As for the interface, it is mostly black and uses Apple’s San Francisco typeface.

Release date

Apple wants Apple Watch to be all about health and fitness, rather than just communication and timekeeping. The upcoming Activity app will therefore be an important feature in Apple's eyes. It's expected to release with Apple Watch later this month. Apple will begin taking pre-orders for the Apple Watch on 10 April, ahead of an 24 April launch.

The Workout app is different from Activity in that it shows real-time stats for calories burned, time, distance, and pace for your runs, jogs, walks, cycling, and indoor equipment like elliptical. The idea is that you'll see real-time information for the specific cardio training you're doing (rather than generic stats), while you're doing it.

How it works

Apple has a secret, gym-like lab that it's been using to study how people workout. It's compiled years worth of data in order to design a smartwatch that can figure out the exact activity being performed, even if it involves exercise equipment, with the purpose of painting a complete picture of your fitness and the effectiveness of your workouts.

Many fitness devices simply can't do any of this; they'll serve up a generic amount of calories burned based simply on the fact that you're moving, but you won't see detailed information for each specific exercise. The Workout app using the Apple Watch's accelerometer, gyroscope, and heart rate monitor to provide detailed summaries on a range of workouts.

That said, the Workout app cannot track water-based workouts, such as swimming or diving, even though the Apple Watch is water resistant (rated IPX7 under IEC standard 60529). But for land-based workouts, it will display all the necessary stats you need, and it will show you when you're about to or have achieved a goal.

It also displays your last and best training session of each type. The idea is that the Workout app, with help from the Activity app, will not only track specific kinds of workouts, but also chart your progress over time. The Workout app will also adjust to your gait for more accurate results.

While writing in her promotional Apple Watch diary, model Christy Turlington Burns revealed that the Workout app will adapt to a person's stride, meaning it produces more accurate results, something Burns suggested is important due to the difference between running outside and on a treadmill.

Release date

Because Apple hasn't shared many details yet about its built-in apps for Apple Watch, we don't know much else about the Workout app, including what the iPhone companion app looks like and how it differs from the app for Apple Watch, which appears to sport a black and green-coloured interface.

We only know that designers thought a lot about the final design, according to an internal memo dug up by 9to5Mac. We also know Apple wants Apple Watch to be all about health and fitness, rather than just communication and timekeeping. The upcoming Workout app is expected to release with Apple Watch later this month.

AppleScreen Shot 2015-04-01 at 12.06.52 PM

Check out Apple's webpage for more details about its built-in apps for Apple Watch.