Skip to content
Haley Maddox
All type 1 guides
Setup guide · Type 1

Dexcom, Zukka and Nightscout

How one glucose sensor reaches your phone, your watch and everyone who follows you.

Target range

Coll. Haley Maddox · Oct 2026Next guide: Reports →
Start here

What is a Dexcom?

A Dexcom is a continuous glucose monitor (CGM): a small sensor you wear that reads your glucose day and night, with no finger pricks for routine checks.

5 minbetween readings, around the clock
SensorA tiny filament under the skin measures glucose in the fluid between cells.
TransmitterSends each reading to the phone by Bluetooth. On the G7 it is built into the sensor.
Phone appThe official Dexcom app shows the number, trend arrow and graph, and sounds high and low alarms.
The big picture

How it all fits together

Your phone does all the work. The Dexcom app and Zukka both read your sensor, Zukka alerts your watch and uploads to Nightscout, and everyone else follows from there.

YOUR PHONE AND WATCH 3 WAYS FAMILY CAN FOLLOW Dexcom sensor A reading every 5 minutes Bluetooth direct to watch (G7) Apple Watch Dexcom direct + Zukka alerts Zukka (master) Reads sensor, alarms Dexcom app Official app, keep running Nightscout site Your own URL + secret Dexcom Share Turned on as a backup 1 · Zukka app Recommended, own alarms 2 · Nightscout website Any browser, no app 3 · Dexcom Follow Backup, up to 10 people alerts uploads one-tap link URL + read-only token Share email invite SNAQ (meal tracker) Reads Dexcom on its own Optional extra, not part of Nightscout Solid: the main setup. Dashed: Dexcom's backup sharing. Green: SNAQ, separate from Nightscout.
Part 1

Your setup

Everything in this part happens on the iPhone and Apple Watch of the person wearing the Dexcom, in this order: Dexcom app, Nightscout site, Zukka, then the watch.

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 your Nightscout site

Nightscout is a free, open-source website that stores your readings in the cloud. It is the hub every follower reads from.

  • Who made it: parents of children with type 1 diabetes. Volunteers still run it, and it is not a Dexcom product.
  • What it does: receives readings from Zukka, stores them, and shows a live graph at your own web address.
  • What you need: a site, either self-hosted with the free guide at nightscout.github.io or from a paid hosting service such as Nightscout Pro, which Haley uses.
  • Write down two things: the site URL and the API secret, a password of at least 12 characters. Your Zukka needs both to upload. Keep the secret private.
  • Make a follower token: sign in to the site with the API secret, open Admin Tools, and under Subjects tap Add new Subject. Name it "Family", give it the readable role, and save. Copy the token it shows. Followers use this instead of the secret: it can only view, and deleting the subject cancels it.

Here's what a finished setup looks like. These are made-up example values; yours will have your own address and token.

Example · made-up values
Nightscout URL
https://yourname.example.com
Read-only token
family-0123456789abcdef
One-tap link
https://yourname.example.com/?token=family-0123456789abcdef
API secret
Never shared. Only the uploading phone needs it.
70180250 12 am6 am12 pm6 pm12 am
Example data, not real readings. A follower's view looks like this: one day of glucose in mg/dL, with the 70–180 target range shaded.
Good to know: Nightscout is a second screen, not a medical device. Use the Dexcom app or a fingerstick for treatment decisions.

Source: What is Nightscout?

Step 3

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 alarms, feeds your watch and uploads to Nightscout.

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. Open Nightscout settings, turn on upload, and enter your site URL and API secret. Tap Test if offered.
  5. Set up your alarms in Zukka using the recommended settings below. Check they sound with the phone on silent.
  6. Open your Nightscout URL in a browser and confirm your latest reading shows up.

Recommended alarm settings

Your alerts should come from Zukka, so they also reach your watch. These are the settings Haley uses, 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.
Haley's alarms in Zukka
AlarmGoes offSound
!Very low70 or belowlow
Low80 or belowHaley uses 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 Haley's 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 4

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 5.

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 5

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, on your watch face, and on your Nightscout site.

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

Part 2

3 ways family can follow

Pick the first one that works for each person. Zukka is the main way. The Nightscout website covers anyone without an iPhone, and Dexcom Follow is a backup.

WayPhoneAlarmsNeeds
1 · Zukka appiPhoneYes, each person sets their ownNightscout URL + read-only token
2 · Nightscout websiteAny phone or computerOnly while the page is openOne-tap link
3 · Dexcom FollowiPhone or AndroidYes, set per followerEmail invite from your Dexcom app

1Zukka app

Recommended

The best way for family on iPhone: the same graph you see on your own phone, with alarms each person sets for themselves. It's set up once and never needs touching when you change sensors.

Full follower setup below

2Nightscout website

Any device

For Android phones, computers, or anyone who just wants a quick look. Nothing to install.

  1. Open the one-tap link from the person you follow: their Nightscout URL with /?token= and their read-only token on the end. There's no login. The example graph in Step 2 shows what opens.
  2. Save it: in Safari tap Share, then Add to Home Screen. In Chrome, use the menu and Add to Home screen.

Nightscout can sound alarms in the browser, but only while the page stays open.

3Dexcom Follow

Backup

Dexcom's own sharing. It doesn't use Zukka or Nightscout, so it keeps working if either one is down.

  1. On your phone, open the Dexcom app, tap the Share icon and follow the screens.
  2. Tap Invite Followers and enter the follower's email. Pick their alerts and whether they see the graph.
  3. The follower installs Dexcom Follow (iPhone or Android), opens the email invite and taps Start Following.
10followers at most through Dexcom Share

Sources: Dexcom, Share and Follow setup · Dexcom Follow FAQ

Tip: ways 1 and 2 only update while your phone is online, since your Zukka app does the uploading.
Way 1, step by step

Zukka follower setup

For each family member with an iPhone who wants to follow you. It takes about five minutes and only happens once. They'll need your Nightscout URL and your read-only token.

On the follower's iPhone

Follower
  1. Install Zukka from the App Store. When asked, allow notifications and critical alerts so alarms sound even on silent.
  2. Open Settings and set the data source to Follower.
  3. Choose Nightscout as the follower source.
  4. Enter the Nightscout URL, then the read-only token in the token field. The example card in Step 2 shows what both look like.
  5. Go back to the home screen and wait a few minutes. The latest reading and graph should appear.
  6. Set alarms. Start with the recommended settings. They change only this phone, never yours.
  7. Leave Zukka running in the background. Don't force-quit it, or alarms stop.

Optional: on the follower's Apple Watch

Once
  1. Install the Zukka watch app from the Watch app on their iPhone.
  2. Allow Zukka notifications on the watch.
  3. Add the Modular Duo face with the Zukka graph at the bottom.

Menu names follow xDrip4iOS and may differ slightly in Zukka.

Optional extra

SNAQ, the meal tracker

SNAQ estimates the carbs, protein and fat in a meal from a photo, then shows how that meal moved your glucose afterward. It's a Dexcom partner app, so it reads your Dexcom data directly.

Good to know: SNAQ sits outside the Nightscout setup. It doesn't send anything to Nightscout or Zukka, and followers won't see it.
  1. Install SNAQ - Diabetes Food Tracker from the App Store on your phone.
  2. In SNAQ's settings, connect your Dexcom account.
  3. Snap a photo of each meal. SNAQ lines it up with your glucose curve.

Sources: Dexcom: SNAQ connected app · SNAQ on the App Store

What it costs

Costs

Most of the setup is free. The two paid pieces are Nightscout hosting and SNAQ Premium. Haley pays for both.

App or servicePriceNotes
Dexcom appFreeSensors are bought separately.
ZukkaFreeFree on the App Store, including the watch app.
Dexcom FollowFreeFor up to 10 followers.
Nightscout hosting£3.99/month
or £39.90/year		Nightscout Pro's listed prices, in British pounds. Also £19.95 for 6 months. Self-hosting is possible for little or nothing.
SNAQ Premium$60/yearOr $27 every 3 months, or $96 for 3 years, on SNAQ's website. App Store prices vary by plan.

Prices checked October 2026 and may change. Sources: Nightscout Pro shop · SNAQ Premium pricing · Zukka on the App Store

When something's off

Troubleshooting

ProblemCheck first
Zukka on your phone shows no readingsThe Dexcom app is open in the background and showing readings; Bluetooth is on.
Nightscout stops updatingYour phone has internet; the URL and API secret in your Zukka app are exact, with no trailing slash.
A follower's Zukka app falls behindThe Nightscout site loads in a browser; the follower's URL and token match.
Your watch shows no alertsZukka notifications are allowed on the watch; the watch is paired and nearby.
Dexcom watch app shows a small phone iconThe watch lost its direct link and is reading through the iPhone. Reopen the Dexcom watch app and pair to the sensor again.
Dexcom Follow says "Removed"Sharing was turned off for that follower. Re-invite from your Dexcom app.
Before you're done

Setup checklist

Your setup

Followers

0 of 11 done

Sources