Runback

Local Android training app for running and strength training, with a standalone Wear OS app. Everything stays on the device: no account, no cloud, no required setup.

Website: runback-training.vercel.app

Runback records runs and strength training with your phone and watch, imports your history from other apps, and shows what the data contains: pace, heart rate, kilometer splits, running form, sets, muscles, and comparisons with your recent workouts. Missing values appear as “–” rather than an estimated number.

Language

The app is available in German and English. Switch it under Settings → Language. The default is the device language.

Data

• Import from Garmin, Strava, Fitbit, Google Fit, Apple Health, Samsung Health, Mi Fitness, Polar, Strong, and others — see Imports.
• Backup as a ZIP with everything Runback knows; restore onto a fresh installation.
• Export of a run as GPX, run reports, and strength training as ZIP.
• Health Connect read and (per run, explicitly) write.
• BLE sensors for heart rate and running cadence.
• Weather only once enabled, via Open-Meteo.
• Own server optional, self-hosted, with a read-only copy of shared data — see server/README.md.

What you see in the app

Today and History are fixed tabs. Up to two more active features can be pinned to the bar: Plan, Progress, Statistics, Routes, Templates, or Soreness. Everything else is under All features.

• Today — What do I do now? A week strip, today’s workout as a card with a start button (sport, purpose, template, and pace/heart rate target in the start sheet), goal progress, reporting soreness, and the latest workouts.
• History — What have I done? Workouts grouped by week with totals. Detail view with map, metrics, insights, feeling, and splits.
• Challenges (optional, off by default) — Set daily count goals, log amounts with custom quick buttons on Today, and review totals and goal-day streaks. Plan shows the recorded counts on each day.
• Plan — What is planned and what did I do? One screen with the month (or, less prominent, the week): a small symbol per workout, gray when planned, green when done. Tap a day to change just that day. Above it the period's workouts, time, and km, marked ▲/▼ against the usual amount of the periods before.
• Progress — How close am I to my goal? Running and strength training separately, each with its own goal: for running the goal estimate from actual runs, for strength a load for one exercise against your heaviest matching set of the last 12 weeks.
• Statistics — How am I developing? Runs and strength training over weeks, personal bests, consistency, and body values.
• Settings (gear icon in the header) — Features and navigation, All features, Voice & vibration (announcements, voice, cues while running and at the end of a rest), Devices & connections (watch, BLE, Health Connect, weather), Own server, Your data (import, export, backup, delete), Calculations, Weekly plan (what repeats every week, e.g. runs on Tuesday and Friday, the “Pull” template on Monday). Language is here too.

Under Features you choose what Runback shows and when it asks: areas (running, strength training, cycling), soreness and how often it is asked (by default after strength training), the blocks on Today, display during recording, the rest timer, and more. Under Navigation you choose the tabs. What is switched off disappears from the app; data is kept.

Goals (optional)

Running and strength training are separate areas, each with its own optional goal and date; if you only do one, you see nothing of the other. A running goal with distance and time feeds the goal times; a strength goal names an exercise, a load, and reps. Runback gives no training recommendations: after a run it shows what the data contains, compared with your earlier runs. Details, data basis, and uncertainty are under “Details”.

Installation

Test releases each contain a phone and a Wear APK, signed with a fixed public debug key. No development server needed.

adb -s PHONE_SERIAL install -r runback-phone-*.apk
adb -s WATCH_SERIAL install -r runback-wear-*.apk

For the watch: enable developer options and wireless debugging, then adb pair and adb connect. adb install -r keeps existing data. Checksums: sha256sum --check SHA256SUMS.

This is test software. Real-world GPS/sensor accuracy, battery use, and long background recording have not been fully verified on real devices; personal forecast models remain locked until validated.

Development

Node 20.19+ or 22, JDK 17/21, Android SDK 36, NDK 27.1.12297006.

npm ci
npm run check
# Include native tests and Android lint when changing Kotlin or Android resources.
npm run check -- --android
# Build standalone APKs separately.
cd android && bash ./gradlew :app:assembleRelease :wear:assembleRelease

check runs ESLint, tooling tests, TypeScript and Jest, stopping on the first failure. Jest uses Europe/Berlin, matching CI. For native checks, set ANDROID_HOME (or ANDROID_SDK_ROOT) to your SDK, or set sdk.dir in the ignored android/local.properties; Java must be on PATH or selected through JAVA_HOME. The runner resolves the repository and Android directories itself. Windows uses gradlew.bat. CI checks the app and the server depending on the changed files; shared logic, dependencies and CI changes check both. Pure website and docs changes build no APKs. For app changes on main, CI publishes a prerelease and reuses the identical, successful PR build where possible (.github/workflows/android.yml).

Documentation

• Spec — goal, mindset, ground rules.
• Design language — how surfaces look and speak.
• Glossary — German and English UI terms → code names.
• Imports — which exports come from where and what becomes of them.
• Motion data — export strength-training movements and use them for a model.

The repository is public; the license has not been decided yet.