What Is the SelfSense App?
SelfSense is an iPhone and Apple Watch app that trains the structure of your variability, not just its amplitude. It tracks heart rate variability and movement variability in real time, computes DFA alpha on both, and uses the readings to help you build a nervous system that is adaptive — alert when needed, settled when not, able to switch between the two.
It is a free TestFlight beta. You can install it on iPhone, sync it to Apple Watch, optionally pair a Polar H10 or Movesense sensor, and start tracking within a few minutes.
What the App Actually Does
- Tracks fractal HRV in real time using DFA alpha 1 on RR-interval data from Apple Watch, Polar H10, or Movesense. The reading tells you whether your nervous system is in stress, rest, or the adaptive (fractal) state.
- Tracks adaptive movement variability using the same DFA method on accelerometer and stride-interval data. Useful for walking, running, postural work, and detecting the onset of fatigue or bracing.
- Entrains breathing fractally, not with a fixed square or resonant pattern. The breathing guide uses a fractal rhythm derived from natural variability research, so the body learns to be variable rather than to follow a single cadence.
- Sends real-time haptic feedback through Apple Watch so you can use the app without staring at the screen.
Why Fractal, Not Just Calm
Most HRV apps treat variability as a number to maximise. SelfSense treats it as a structure to listen to. The difference matters: you can have high HRV that is rigid and cyclical (rest), or high HRV that is fractal and responsive (adaptive). Only the second one means your nervous system can actually meet the next thing that happens.
The longer version of this argument lives in How SelfSense Works — the science, the DFA method, and why fractal variability is the more honest target.
Where to Go Next
- Try it. Join the TestFlight beta — free.
- Set it up. How to use SelfSense — step-by-step setup for iPhone, Apple Watch, and optional sensors.
- Understand the science. How SelfSense Works — full explanation of fractal variability, DFA alpha, and the underlying research.
- Group sessions. The SelfSense Server — an overview of the optional companion server that makes multi-sensor and multi-person sessions possible.