Strimma

Android CGM companion app. Receives glucose readings from CGM apps, displays them with an interactive graph and persistent notification, and pushes to Nightscout.

A modern alternative to xDrip+ — built with Kotlin, Jetpack Compose, and Material 3.

Features

• Companion Mode — reads glucose from any major CGM app's notification (CamAPS FX, Dexcom G6/G7/ONE, LibreLink, Libre 3, Juggluco, xDrip+, Diabox, Medtronic, Eversense, and more)
• xDrip Broadcast receiver — receives com.eveningoutpost.dexdrip.BgEstimate intents from any app that broadcasts in xDrip format
• Nightscout upload — pushes readings to any Nightscout server via /api/v1/entries with retry and offline resilience
• Interactive graph — pinch to zoom, pan, scrub-to-inspect with tooltip, 24h minimap with draggable viewport
• Prediction with threshold warnings — least-squares curve fitting (linear/quadratic) on last 12 min of readings, with "Low in X min" / "High in X min" warnings when trending toward thresholds
• Persistent notification — collapsed and expanded layouts with mini graph, BG value, trend arrow, and delta
• Status bar icon — current BG rendered as a bitmap icon
• Glucose alerts — urgent low, low, high, urgent high, and stale data, each with its own notification channel for independent sound/vibration/DND settings
• Home screen widget — Glance widget with BG, trend arrow, delta, mini graph, and configurable opacity
• Statistics — time in range, GMI, average glucose, CV%, coverage, with CSV export
• Units — mmol/L and mg/dL with one-tap toggle
• BG broadcast — emits xDrip-compatible intents so watches and other apps (AAPS, GDH) can receive data
• Dark / Light / System theme

Data Flow

Libre 3 sensor
  --> CamAPS FX (BLE)
    --> Android notification
      --> Strimma NotificationListener
        --> Room DB
          --> Nightscout /api/v1/entries
          --> Notification (graph + BG)
          --> Alerts
          --> Widget
          --> BG Broadcast (optional)

Strimma does not connect to the sensor directly. It reads the glucose value from your CGM app's ongoing notification (Companion Mode) or receives it via xDrip broadcast.

Requirements

• Android 13 (API 33) or newer
• A CGM app that shows glucose in its notification (for Companion Mode)
• A Nightscout server (optional, for cloud upload)

Setup

1. Install

Download the latest APK from GitHub Releases and install it.

Since the APK is sideloaded (not from Google Play), Android restricts some permissions by default. You need to allow restricted settings for the app you used to install the APK (e.g. your file manager or browser):

1. Go to Settings > Apps and find the app you used to open/install the APK (e.g. "Files by Google", "Chrome", or your file manager)
2. Tap the three-dot menu (top right) and select Allow restricted settings
   • On some devices this is under Settings > Apps > Special access > Install unknown apps
3. You may need to confirm with your PIN/biometrics

This is a one-time step. Without it, Android will not let you grant Notification Access to Strimma in step 3 below.

2. Open Strimma

Launch the app. It will ask for notification permission — grant it so Strimma can show its persistent glucose notification.

3. Grant Notification Access (Companion Mode)

Strimma needs to read notifications from your CGM app to get glucose values:

1. Open Strimma Settings (gear icon)
2. Under Data Source, select Companion Mode
3. Tap Grant Notification Access when prompted
4. Find Strimma in the system list and enable it

If Strimma doesn't appear in the notification access list, you skipped step 1 above (Allow restricted settings).

4. Configure Nightscout (optional)

1. In Strimma Settings, enter your Nightscout URL (e.g. https://my-ns.example.com)
2. Enter your API secret
3. Readings will push automatically on each new value

5. Configure Alerts (optional)

Each alert type (urgent low, low, high, urgent high, stale data) has its own Android notification channel. You can:

• Enable/disable each alert independently
• Set custom thresholds
• Tap Sound to open Android's channel settings for that alert, where you can pick a ringtone, vibration pattern, and whether it bypasses Do Not Disturb

6. Alternative: xDrip Broadcast

If your setup already broadcasts in xDrip format (from AAPS, Juggluco, xDrip+, etc.):

1. In Strimma Settings > Data Source, select xDrip Broadcast
2. No notification access needed — Strimma receives data via broadcast intent

Build from Source

git clone https://github.com/psjostrom/strimma.git
cd strimma
./gradlew assembleDebug

Install on a connected device:

./gradlew installDebug

Run tests:

./gradlew testDebugUnitTest

Requires Java 21 (configured in gradle.properties).

Architecture

Single-module app. 35 Kotlin source files, ~3,800 lines.

Package	Purpose
data/	Room entities, DAO, SettingsRepository, DirectionComputer, GlucoseUnit
graph/	Shared graph constants, color functions, Y-range computation, prediction curve fitting
network/	NightscoutClient + NightscoutPusher (Ktor, /api/v1/entries)
notification/	NotificationHelper (collapsed/expanded with graph), GraphRenderer, AlertManager
receiver/	GlucoseNotificationListener, XdripBroadcastReceiver, GlucoseParser, DebugLog
service/	StrimmaService (foreground), BootReceiver
ui/	Compose screens (Main, Settings, Stats, Debug), MainViewModel, theme
widget/	Glance widget, config activity

Stack: Kotlin, Jetpack Compose, Material 3, Room, Hilt, Ktor Client, Coroutines/Flow, DataStore, EncryptedSharedPreferences, Glance.

Tests: 77 tests (57 unit + 20 integration) running on JVM via Robolectric. No emulator needed.

Contributing

All changes to main go through pull requests — direct pushes are blocked. PRs require:

• Signed commits (GPG or SSH)
• Linear history (squash or rebase merge only)
• All review conversations resolved

Fork the repo, create a branch, and open a PR when ready.

Acknowledgments

Strimma exists because of xDrip+. Its feature set, UI patterns, and data pipeline are directly inspired by xDrip+'s decade of pioneering work. The CGM package list in Companion Mode is based on xDrip+'s UiBasedCollector.coOptedPackages.

Strimma is not a replacement for xDrip+ — it's a modern alternative built on a different architectural foundation, offering the CGM community another option.

License

Strimma is free software licensed under the GNU General Public License v3.0.