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Onus User Guide

Onus is a straightforward workout tracker for iPhone and Apple Watch: build programs, log sets in real time, and see your progress and personal records over time — with no account, no ads, and no data leaving your device (except to your own private iCloud, if you choose to back up). This guide walks through the app's main features.

Getting Started

Onus has no sign-up and no account — open the app and start logging. The first time you launch it, you'll be asked to pick one of the built-in preloaded programs to start as your Current program (you can change or ignore this later); after that there's nothing to configure before your first workout. Your data lives on your device (and syncs to your paired Apple Watch).

The app is organized into four tabs: Home, History, Workouts, and Settings. The exercise library lives inside Settings rather than its own tab (see Exercise Library).

Home

Home is your launch pad. From here you can:

Starting a Workout

There are two ways to start a session:

Logging a Workout

The active workout screen lists each exercise as an expandable card. For each set you log:

You can add or remove exercises and sets mid-workout, and a running elapsed time is always visible in the toolbar. When you're done, Finish Workout saves it to your history; Discard Workout throws it away.

If a workout was started from a template and you changed the plan on the fly (added/removed an exercise or set, changed a target), Onus shows a Template Changes review after you finish, listing what changed by exercise so you can accept the changes into the template or reject them and keep the template as-is.

Supersets & Circuits

Group two or more exercises to perform back-to-back, round by round. Group exactly two exercises and Onus calls it a Superset; group three or more and it's a Circuit — the same feature, just a different label. To create one, multi-select exercises in a workout or template and tap Group as Superset/Circuit.

Each group has its own name and settings: how many sets make up a round, rest between exercises within a round (for circuits of 3+), and rest after a full round before starting the next one. During a workout, the group's card shows every member and only advances once all of them have completed the current round — not just the first one you finish.

Rest Timer

Completing a working set automatically starts a rest timer with a progress-filled bar. You can adjust the remaining time in either direction or skip it outright, and it keeps counting even if you background the app, alerting you with your chosen sound when it ends.

Personal Records

Onus automatically detects when a completed set is a new personal record for that exercise and celebrates it with an on-screen trophy animation. PR sets are marked with a trophy badge everywhere they appear — the active workout, workout summaries, history, and Progress Graphs (where PR points are drawn larger and in a distinct color) — so your best lifts are always easy to spot.

Workouts & Programs

The Workouts tab has two sub-tabs:

Both programs and workouts are fully editable — reorder exercises and sets, group exercises into supersets/circuits, adjust targets, or delete what you no longer need.

Exercise Library

Browse the full built-in exercise catalog from Settings → Exercises → Exercise Library, filterable by muscle group, equipment type, and search text. Each exercise entry shows its primary and secondary muscles and equipment, and has a lookup menu for form instructions via YouTube, muscleandstrength.com, musclewiki.com, or the free-exercise-db project — opened in an in-app browser so you never leave Onus.

You can also add your own custom exercises with a name, muscle group, and equipment type — useful for movements not in the built-in catalog or gym equipment that's a little different from the standard. When adding exercises to a workout, you can multi-select several at once instead of adding them one at a time.

History

Every completed workout is logged with:

History has a Progress sub-view alongside the chronological list — see Progress Graphs below. You can also set a Start Date in Settings to limit how far back both views look.

Progress Graphs

Track how an exercise is trending over time as a line chart, from History → Progress. Tap Add Graph to pick any exercise — from a program, a specific workout, or your other logged exercises — and Onus plots it going forward.

Each graph can show 1RM Estimate, Top Set, Volume, or Max Reps, over the last 30, 60, or 90 days or All Time, with an optional trend line. PR sets stand out as larger, highlighted points. Use Filter Graphs to narrow which graphs are shown and Manage Graphs to bulk-edit or delete them. If you'd rather not manage graphs by hand, turn on Only Show Current Program in Settings and Onus keeps your graphs in sync with your Current program's exercises automatically.

Apple Watch App

Onus runs as a standalone Apple Watch app — workouts can be started, logged, and finished entirely from the wrist, even without the iPhone nearby.

Settings

Onus is tuned to how you train:

Data Export, Import & iCloud Backup

From Settings you can:

Apple Health Integration

With permission, Onus reads heart rate, active energy burned, and body mass (the last only to estimate calories when the Watch doesn't supply a measured value) to enrich your workout summaries. Workouts tracked with the Apple Watch are also written back to Apple Health so they show up alongside your other activity; workouts logged from iPhone alone (without the Watch) aren't written to Health. This is all handled by Apple's HealthKit framework directly on your device — see the Privacy Policy for details.

Privacy

Onus doesn't collect, transmit, or sell any of your data — full details are in the Privacy Policy.

Support

Have a question, found a bug, or want to request a feature? onus.support@gmail.com