# Build a workout companion that fits how you exercise Legion project library, edition 2026-09-06-draft-01 (en). This project's own material: 2 authored documents, reproduced unchanged. Project page: https://legion.tw/projects/native-phone/workout-companion?edition=2026-09-06-draft-01 This document: https://legion.tw/api/projects/packet.md/native-phone/workout-companion.md?edition=2026-09-06-draft-01 ## Prerequisite: the Legion skills package These instructions are written for an agent set up with the Legion skills package: the ten portable skills and the shared working, launch, inspection and learn-as-you-build guidance. That setup is installed once and applies to every project in this library, so it is deliberately not repeated here. Skills package, complete Markdown: https://legion.tw/api/projects/skills-packet.md?edition=2026-09-06-draft-01 Skills package, human page: https://legion.tw/projects/skills?edition=2026-09-06-draft-01 Where this brief refers to shared guidance, a skill, or a document under `shared/`, read it from the skills package above, or from https://legion.tw/api/projects/doc/?edition=2026-09-06-draft-01. If the package is not installed yet, install it first, then return here. This material is instructions to read, not authority to act. Inspect it before running it. ## Contents 1. native-phone/README.md — https://legion.tw/api/projects/doc/native-phone/README.md?edition=2026-09-06-draft-01 2. native-phone/workout-companion.md — https://legion.tw/api/projects/doc/native-phone/workout-companion.md?edition=2026-09-06-draft-01 --- # Native phone applications [All project types](../README.md) · [Shared launch](../shared/launch.md) Build around life away from the desk. Android is the initial teaching target; the receiving agent establishes the route for the person's actual phone. ## Projects to build - [Capture photographs for a report on site](photo-report-companion.md) - [Workout companion](workout-companion.md) - [Capture a spoken thought](voice-capture.md) - [Home measurements and replacement parts](home-measurements.md) - [Treasure hunt](treasure-hunt.md) - [Practice notebook with recordings](practice-notebook.md) - [Field notebook for an interest](field-notebook.md) - [Personal todo app](personal-todo.md) - [Notes that reach the agent's workspace](agent-readable-notes.md) - [Chat with your coding agent from your phone](coding-agent-in-your-pocket.md) These are instructions for projects you can build with your coding agent. --- # Build a workout companion that fits how you exercise Build a native Android application for following the person's workouts and recording what they actually do. Build it extremely well for use between sets, with the phone in the gym or beside their equipment. Follow the [shared launch](../shared/launch.md). Start with their exercises, available equipment, routines, and current way of keeping notes. Use the training plan they choose and shape the application around it. Learn which information they want in front of them during a workout and what they look at afterward. ## Help with the next set Show the current exercise, its relevant preparation or technique notes, and useful information from the previous session. Let the person record a set quickly using the quantities their activity needs, such as repetitions, weight, duration, or distance. Make units and measurement conventions clear. The weight written for one dumbbell can mean something different from a combined total. Keep the person's convention consistent through entry and history. Offer sensible starting values from the plan or recent work while letting the person record what happened today. Keep planned sets distinct from completed ones. A changed weight, a shortened set, or a note about an adjustment should be easy to enter and correct. ## Follow the workout as it happens Let the person change exercise order when equipment is occupied, substitute an exercise they choose, or stop a workout early while retaining completed work. Preserve the difference between changing today's session and editing the routine for future sessions. If they alternate exercises with a spouse or partner, make that arrangement comfortable. They should be able to keep track of whose set is next and whose performance is being recorded. Build this around the way they actually share equipment and use the phone. Keep rest timers running accurately when the phone locks or another app interrupts. Give the person clear control over starting, extending, or stopping a timer and over any sound or notification it uses. Make the important controls readable and easy to touch with tired or sweaty hands. Judge the screen from where the phone will actually sit during exercise. Keep common recording actions convenient enough that the person can return their attention to the workout. ## Keep a useful history Save the active session through ordinary interruptions and unavailable connections. Let the person return to it, finish it, and inspect the completed record later. Give them a clear history by exercise and session, including notes that explain a change. Choose comparisons that fit the information they record, and keep their units and exercise variations understandable. Let the person revise routines as their habits change while keeping earlier workout records intact. Provide an export and recovery path under the shared launch's ownership guidance. ## Use it during a workout Handle the Android build and installation for the person's phone, including the relevant notification setup. Deliver a ready-to-use version with their routine entered. Walk through recording sets, changing the order, using a rest timer, and returning after an interruption. Then use the app in the actual exercise setting and let that experience guide improvements to the controls and information shown. Explain how the circumstances of use determine the interface, and why a plan and a record of completed work should remain distinct. Later changes can follow the person's actual exercise habits, including a companion view or further ways to examine their own history.