Developer Diary
Notes from the track
Notes from the track — how and why Apex Run's features were built, from the perspective of a runner who codes.
August 2026
What kind of run was that, really?
A runner on Reddit asked whether you should walk or run during recovery pace. It highlighted a universal training trap: running easy runs too hard. Here is how we turned heart rate zones and pace variability into automatic run classification.
August 2026
Your Home Screen keeps up now
Finish a run and your widget picks it up automatically — distance, pace, and route — usually within seconds, without opening the app first. Here's why this update changes how widgets feel.
August 2026
Accidentally stopped your workout? Merge it back into one
Sweaty fingers hitting 'End Workout' instead of 'Pause' during a water break shouldn't split your 21K into two separate fragments. Apex Run now lets you merge adjacent runs into a single continuous workout right inside the app.
July 2026
Why did the same route measure differently on two separate days?
A morning conversation with a friend led to comparing two 14km FIT files from the exact same loop ran on different days. What started as a quick file inspection turned into building a new tool — and uncovering how watch firmware sensor fusion really works.
July 2026
How recovered are you, actually?
Every runner knows they should recover. Almost nobody knows whether they actually did. Recovery brings HRV, sleeping heart rate, and sleep together into a transparent daily readiness signal.
June 2026
Running slower, getting faster
MAF training theory says run slow enough and your easy pace gets faster. I already had the heart rate data. I just needed to look at it differently.
May 2026
The photos were on my phone. The run was in the app.
After crossing a half marathon finish line, the chip time logged automatically, the GPS trace was perfect — and the finisher photo was somewhere else entirely. Trophy Room puts them back together.
May 2026
Stolen from the race report
Race reports have always shown 5km splits. I've been reading them for years without thinking twice about it — until after my last half marathon, when I finally thought: why don't we have this in Apex Run?
April 2026
Your runs, drawn
Numbers can't tell you which run was the hilly loop, the long out-and-back, or the lazy lap around the lake. Your GPS route can. Gallery mode shows your run list as a stream of route maps — one glance and you know exactly which run was which.
April 2026
The facts it couldn't show
Same friend. He liked Running Facts for his easy runs. Then he finished an outdoor interval and sent me another screenshot — average pace, no work pace, no rest pace, nothing split. So I built an interval edition.
April 2026
I started hiking. Then I started running.
I climbed a hill recorded as a hiking workout, then broke into a run without switching the activity type. Apex Run only tracks runs — so that effort just disappeared. This feature exists because of that day.
April 2026
Fast or slow, at a glance
After a long run, scrolling through 20+ splits and mentally comparing each pace to the average is tedious. So I drew a line. Orange bars are faster than average. Blue bars are slower. Now you see the whole run's rhythm instantly.
April 2026
One line, two stories
A share card that draws your elevation profile as a curve — then colors it by heart rate zone. The shape tells you where the terrain went. The color tells you how hard your body worked to get there.
April 2026
Stop searching for the beat
Every time I wanted to run at 180 spm, I'd go find an MP3. One day in the middle of that search, the thought landed: why isn't this just in the app?
March 2026
Nutrition facts, but for your run
Nutrition facts exist because what goes into your food deserves a complete breakdown. Running data felt the same way — so I borrowed the format.
March 2026
The number that made me want to tap
The first version of Best Effort was just numbers. Every time I looked at it, I wanted to tap it — to see where on the route that fastest split actually happened.
March 2026
A share card that actually shows the workout
A friend complained that sharing his interval run looked identical to any easy jog. He was right. So I built a share template that actually shows the structure of an interval workout — work bars, rest bars, and the numbers that matter.
February 2026
Your training, on the home screen
Two widgets that put your running data on the home screen — a latest run glance and a weekly stats summary with a trend sparkline. No app launch required.
February 2026
Splits, all the way down
Some runners just want the numbers. All of them. Apex Run's split detail view calculates every metric for each individual split — pace, heart rate zones, cadence, elevation, and more — for the data lovers in the room.
January 2026
Bringing VO2 max to your run
VO2 max is the single number that best captures your aerobic fitness — but Apple buries it in the Health app, disconnected from any specific run. Apex Run reads it from HealthKit and ties it back to the run that produced it.
January 2026
Your run list, your metrics
Distance and pace aren't always what you care about. During a heart-rate base-building block, I wanted HR front and center. During a power training cycle, I wanted watts. The run list should show you what matters right now — not a fixed default.
January 2026
Zero cold start
Most running apps greet you with an empty screen. Your years of runs, sitting in Apple Health, ignored from day one. Apex Run was built to fix that — and here's exactly how the sync works.
Feature Requests
What should I build next?
I’m a solo developer and an avid runner. Every feature in Apex Run started from a frustration on my own runs — or an email from someone like you. I read everything and take ideas seriously.
✉ Send me your idea