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Haley Maddox
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Make your own · Set up your tech

Set up your tech

Your Dexcom, your phone and your watch, step by step. It all happens on the iPhone and Apple Watch of the person wearing the Dexcom.

Want to see mine first? My tech setup →

Coll. Haley Maddox · Oct 2026Next: Followers →
Step 1

Pair the Dexcom app

The official Dexcom app pairs with the sensor first. Keep it installed and running, because Zukka reads your readings alongside it.

  1. Install the Dexcom app that matches the sensor (G7 or G6), then sign in or create a Dexcom account.
  2. Pair the sensor using the in-app steps. Wait for warm-up to finish and readings to appear.
  3. Leave the app running in the background. Don’t force-quit it.

Source: xDrip4iOS docs, reading from the Dexcom app

Step 2

Set up Zukka on your phone

Zukka is a free iPhone app built on the open-source xDrip4iOS. On your phone it is the master: it reads your sensor, sounds your alarms and feeds your watch.

Your iPhone

Master
  1. Install Zukka from the App Store. Allow Bluetooth, notifications and critical alerts.
  2. In Settings, set the data source to Master.
  3. Add the CGM and pick your Dexcom model. With a G7 or Stelo, Zukka always reads alongside the Dexcom app. With a G6, turn on Read from Dexcom app.
  4. Set up your alarms in Zukka using the recommended settings below. Check they sound with the phone on silent.

Recommended alarm settings

Your alerts should come from Zukka, so they also reach your watch. These are the settings I use, with one change: a more careful low alarm at 80 instead of 75. Each one runs all day, starting at 12:00 am.

Zukka Edit Alarm screen showing Very Low 70, Low 75, Fast Drop 10 under 120, High 140, Very High 180, and Fast Rise 10 over 160, all starting at 12:00 am.
My alarms in Zukka
AlarmGoes offSound
!Very low70 or belowlow
Low80 or belowI use 75borderline low
!Fast dropFalling 10+ while under 120default
High140 or aboveborderline high
!Very high180 or abovedefault
Fast riseRising 10+ while over 160default

All numbers in mg/dL. ! marks the urgent alarms, shown with a red ! in Zukka. In Zukka: Settings, then Alarms, then tap each one to set its value and sound. These are my settings to start from, so check them with your diabetes care team.

Menu names follow xDrip4iOS and may differ slightly in Zukka. Sources: xDrip4iOS docs · Zukka on the App Store

Step 3

Set up your Apple Watch

Your watch gets readings two ways. The Dexcom watch app pairs straight to your sensor, so readings keep coming when your phone is out of range. Zukka sends your alarms and powers the recommended face.

Set up once

Zukka + watch face
  1. Install the Zukka watch app from the Watch app on your iPhone.
  2. Allow Zukka notifications on the watch so your alarms buzz on your wrist.
  3. Set up the Modular Duo face below.

Every new sensor

Dexcom watch app
  1. Open the Dexcom app on your watch and tap Pair to Sensor.
  2. Tap Pair when the new sensor’s name shows up.

Needs a G7 sensor and an Apple Watch Series 6 or newer on watchOS 10 or later. This is part of the new sensor routine in Step 4.

Recommended watch face

Apple Watch Modular Duo face showing the date, the time, three timers, and a Zukka complication reading 109 with a steady arrow, plus 0 change, updated 8:04 AM, above a glucose graph.
Modular Duo with the Zukka graph
Top leftDate
MiddleTimers (optional)
BottomZukka graph
  1. On your iPhone, open the Watch app and tap Face Gallery.
  2. Choose Modular Duo.
  3. Under Complications, set Top Left to Date and Middle to Timers, or another favorite.
  4. Set Bottom to the Zukka graph complication.
  5. Tap Add, then check the face on the watch shows a fresh reading.

The Timers slot is handy for timing a recheck. If Zukka isn’t listed, open the Zukka watch app once, then look again.

Step 4

Every new sensor

Each time you change your sensor, three things need to find the new one: the Dexcom app, Zukka and your watch. Do them in this order.

New sensor routine

Every sensor change
  1. Dexcom app: start the new sensor using the in-app steps, then wait for warm-up to finish and readings to appear.
  2. Zukka: open the sensor screen, disconnect or delete the old sensor, then add the Dexcom again so Zukka connects to the new one. Wait for a fresh reading.
  3. Apple Watch: open the Dexcom watch app, tap Pair to Sensor, then Pair.
  4. Check: the same number shows in the Dexcom app, in Zukka and on your watch face.

The Zukka watch app and watch face stay put. Only the sensor connections change.

Optional · article on its way

Nightscout

Nightscout is my own site in the cloud for sharing and storing readings. My step-by-step article is on its way. Until then, Nightscout’s own docs walk you through it. You don’t need it for alarms on your phone and watch, or for Dexcom Follow.

Nightscout’s setup docs → Who can follow you without it →
What it costs

Costs

The core setup is free. You pay for your Dexcom sensors, and Nightscout hosting is the one optional paid piece.

Prices checked October 2026 and may change. Source: Zukka on the App Store

When something’s off

Troubleshooting

Zukka on your phone shows no readings
The Dexcom app is open in the background and showing readings; Bluetooth is on.
Your watch shows no alerts
Zukka notifications are allowed on the watch; the watch is paired and nearby.
Dexcom watch app shows a small phone icon
The watch lost its direct link and is reading through the iPhone. Reopen the Dexcom watch app and pair to the sensor again.
Before you’re done

Setup checklist

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Sources