I first began with researching what are the most popular health-related wristwatch apps, there are lots available and recommended. The 3 that continuously appeared as the top choices were, the Fitbit app, Strava App, and MyFitnessPal App. These three seem to be the most commonly used and recommended, they all are based on fitness tracking which there own features.
https://www.a3logics.com/blog/best-apps-for-health-and-fitness/
https://www.androidpolice.com/best-wearable-smartwatch-apps/
The underlined features in each write-up is what is unique to them.
Fitbit App offers the ability to score yourself to let you know targets or to rest, workouts to follow (videos and audio), sleep tracking (score it to), stress management score, mindfulness sessions, blood oxygen levels, GPS, heart rate, location tracking, temperature taking and breathing tracking.
Other features offered on the app are blood glucose tracking, Menstrual health tracking, and Wellness reports. Fitbit is a very personal app that is related to your health as well as fitness, creating a safer way of achieving your goals and taking into account mental health and physical toll as well.
https://www.fitbit.com/global/us/technology/fitbit-app
The Fitbit app on a non-Fitbit watch is nice, it uses the circle shape very effectively on some it isn't as responsive as other times whether this is just because it's on a circle watch face (these images came from the App Store to show its compatibility) which I don't think works so well and as a result the spacing in areas could be improved, putting that aside the icons used is clear and effective, and I like the use of colours to draw attention to areas making it stand out more. I like the use of graphs considering they are a lot smaller screens than your phone but even still they still give you information without details, as you can understand the levels with context.
Strava is more focused on data and accurately recording it as it has the ability for performance analysis, automatic syncing, automatic pausing, activity analysis, recording, editing, splitting (when you are doing multiple activities), and cropping (to remove unwanted and inaccurate). Other features are GPS, heart rate, location tracking, temperature taking, and breathing tracking.
Strava is also used to connect and share your wins and goals, it's a very community-based option that has encouraged and pushed people to become better and stronger with challengers. It also creates the ability to discover new routes from others. It feels like a more adult version of Fitbit all about sharing and connecting.
Stravas app faces are incredibly simple with a very limited colour palette that creates an effective watch face with mostly orange as a clickable option and blue to show results, taking away the colours it's still an incredibly effective design with very limited options only informing you of necessary things like making it clear when you are recording or paused. It creates a really user-friendly design that's incredibly usable and easy to read while exercising. There are very few icons used on this app only the very necessary ones.