MyLoop With Watch
Carl’s personal fork of the open-source Loop closed-loop insulin delivery app, with an Apple Watch companion. Distributed via TestFlight to immediate family only.
What it does
Loop is a closed-loop insulin delivery system. It reads your glucose from a CGM (Dexcom G7), computes how much insulin you need every five minutes, and commands your Omnipod pump to deliver it. You set targets and meal carbs; Loop handles the rest.
The original Loop runs only on the iPhone. MyLoop With Watch adds an Apple Watch companion that takes over when your phone is far from the pod — most commonly overnight, when you’re asleep with the phone in another room.
How it differs from vanilla Loop
| Vanilla Loop | MyLoop With Watch | |
|---|---|---|
| iOS app runs Loop algorithm | ✓ | ✓ |
| Watch app shows status | ✓ | ✓ |
| Watch app runs Loop algorithm | — | ✓ |
| Watch can command the pump directly | — | ✓ |
| Pod handover phone↔watch | — | ✓ |
| Nightscout sync | iOS only | iOS + watch |
The new behavior — watch self-driving, pod handover, and the warming-up state — is genuinely novel and worth understanding. See Watch dynamics for the deep dive.
Closed-loop vocabulary you should know
If you’re new to Loop, the Loop community maintains authoritative docs for closed-loop insulin delivery concepts (basal, bolus, IOB, COB, ISF, etc.) — search “LoopDocs” or “Loop and Learn” for the current site. MyLoop is feature-compatible with vanilla Loop on those concepts.
Liability and informed consent
MyLoop With Watch is a personal fork of community-maintained open-source software. The Loop algorithm has not been reviewed or approved by the FDA, EMA, or any other regulatory body. This app is for personal use by individuals who understand the risks of using non-regulated closed-loop insulin delivery software.
Do not use this app without consulting your endocrinologist and your care team. If anything behaves unexpectedly, fall back to manual insulin delivery (your own basal + bolus pen or syringe) until you can diagnose the problem with Carl’s help.
Privacy
See the MyLoop With Watch privacy policy.
Last updated: 2026-05-01