DIY Fitness Tracker

Creating a Native smartphone App for Workouts

May 11, 2024 - Willem L. Middelkoop

As a little side-project, squeezed between my normal work, I have been working on something of personal interest: a native workout tracking app for iOS. I wanted to make my smartwatch obsolete, instead using my phone to track workouts. How hard could it be to gather detailed sensor data using native Swift APIs?

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I got some magic in my pocket: The app tracking workouts from the background - during recordings it just shows a widget on the homescreen

Nothing makes you feel alive like going outside for some physical action - I love working out!

My bike with Bluetooth sensors connected to my MacBook running Xcode

Screenshots of the app's onboarding process: asking for permissions and guiding new users

Different configurations of realtime data

"Goin' the extra mile": 8 hours on my bike to test battery usage (note: there is still 23% power left!)

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Articles (162)

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2025-03-06 Open-Sourcing Gran Fondo
2025-03-05 Durable Smartphone
2025-02-10 Better Laptop
2025-01-27 Podcast Downloader
2025-01-23 Champions League of Webdesign
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2024-12-19 Data versus Feeling
2024-12-09 The Problem With Bitcoin
2024-11-11 Write your own words
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2024-10-20 Marathon
2024-09-10 I see dead people
2024-05-11 Developing a native iOS app
2024-03-24 Half Marathon
2024-03-05 No, I Won't Build That!
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2023-12-15 Backup Rotation Scheme
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