Documentation

What Gym Buddy is

Gym Buddy is a workout planner and tracker for iPhone with an AI trainer, Rhino, built in. You describe a session in plain language; Rhino writes it as a table of exercises, sets, reps and weights; the app saves it as a workout you can run again and again. While you train, you tick off sets one at a time, adjust weights and reps as needed, and a rest timer counts you down between sets. Every finished session counts towards a streak, appears on an activity heatmap, and feeds your personal records and “last time” reminders.

Your workouts and history are stored on the phone. Only the text of your conversations with Rhino is sent off the device, so that the reply can be generated. See privacy in brief.

Rhino is an AI model, not a qualified coach or clinician. Please read the disclaimer.

Requirements

The home screen

The home screen has three parts, top to bottom:

• Streak banner. Your current streak in days and whether you have trained today. Tap it to open the Progress screen.
• Up next. A workout scheduled for today is recommended first and badged Today. Otherwise the workout you have gone longest without doing is recommended. Rotating through your workouts this way keeps a split balanced without you having to remember what you did last.
• All workouts. Every other saved workout, each with its exercise list and a play button to start it.

The speech-bubble icon in the top right opens a chat with Rhino; the gear next to it opens Settings. The New workout button at the bottom right creates a workout.

Creating a workout with Rhino

1. Tap New workout on the home screen.
2. Type what you want to train and send it. Useful things to include: the muscle groups or goal, roughly how long you have, and what equipment is available. For example, “Upper body push day, about 45 minutes, I have dumbbells and a bench.”
3. Rhino replies with a table: one row per set, with the exercise name, set number, reps and weight. Cardio and timed work (“5 km run”, “plank 60 seconds”) is written in the same table and saved as a cardio or timed exercise. Rhino knows your units and, if you have listed it, the equipment at your gym. The reply streams in as it is written.
4. Not quite right? Keep talking. “Swap the shoulder press for lateral raises” or “make the weights lighter, I am new to this” both work. Rhino sees the whole conversation.
5. When you like it, tap Save in the top right. Rhino tidies the plan into a structured workout and gives it a short name that does not clash with your existing workouts. You land back on the home screen with the new workout in the list.

Training from a workout

Tap Start (or the play button) on a workout to begin. The workout screen shows one card per exercise. Each card shows the current set: its weight, its reps, a row of progress dots and a count such as 2/4 sets. The header counts sets completed across the whole workout.

• Tick a set. Tap the large tick on the right of the card when you finish a set. The card advances to the next set. Once every set is done the card stays ticked.
• Untick a set. Ticked one too many? Press and hold the tick to take the last set back.
• Change the current set. Tap the weight or reps chip to open the set editor.
• See all sets. Tap the exercise name or the progress dots to open the set overview, where you can also add or remove sets and leave a note.
• Last time. Under the chips, each card reminds you what you did the last time you logged that exercise (60 kg × 8, 8, 6 · 5 days ago).

Ticking a set gives a short haptic tap and starts the rest timer. Beat a personal record and the phone buzzes twice with a New record! banner. See records and progression.

The two icons in the app bar open Rhino, who knows which workout you are on and how far through it you are, and the workout editor.

Changing a set

The set editor shows the exercise name and which set you are editing (Set 3 of 4). For a strength exercise it has two fields, weight in your unit and reps; cardio sets have distance and time, timed sets have time and an optional load (see exercise types).

• Tap − or + to step the value. Weight moves in 2.5 kg (or 5 lb) steps; reps move by one.
• For barbell weights the editor shows the plates per side (“20 + 2.5 per side”) assuming a 20 kg or 45 lb bar, so you can load up without arithmetic.
• Tap the number itself to type a value on the keypad. The dialog stays above the keyboard.
• Tap Save to apply the change to that set, or Cancel to leave it as it was.

Edits made during a session are written back into the saved workout when you complete it, so your next session starts from the updated numbers.

The set overview and notes

The overview lists every set of one exercise. Completed sets are ticked and struck through, the current set is marked NOW, and upcoming sets follow. Tap any row to edit that set, useful for planning a drop set, or fixing a number you entered wrongly two sets ago.

• Add set appends a set copied from the last one. The × on a row removes that set (an exercise keeps at least one).
• The note field holds a short reminder, “seat height 4”, “pause at the bottom” shown on the exercise card every session.

Set changes and notes belong to the workout and are saved with it, whether you complete the session or stop early.

Rest timer and supersets

When you tick a set, a countdown strip appears under the progress bar with the rest length from Settings (60, 90, 120 or 180 seconds, or off). +30 s adds time; Skip dismisses it. At zero the phone buzzes and the strip reads Rest over. Go! for a moment. No timer runs after the last set of the workout.

Lock the phone and the countdown carries on as a Live Activity on the Lock Screen and in the Dynamic Island, showing the time left, a progress bar and which set is up next. When rest is over you get a notification, so you can put the phone face down between sets. The first time it appears, iOS may ask to allow notifications from Gym Buddy; the card itself needs no permission. Requires iOS 16.2 or later.

A superset pairs an exercise with the one below it: in the editor, tap the link icon on an exercise row. Linked cards are drawn joined, and ticking a set of the first exercise starts no rest: you go straight into the partner, and rest after that.

Last time, records and progression

• Last time. Each exercise card shows the sets you actually ticked the last time you did that exercise, in any workout, and how long ago that was.
• Records. When a ticked set beats your heaviest weight, or your best estimated one-rep max (weight and reps combined, Epley formula), the phone buzzes twice and a banner says so. Cardio records are longest distance; timed records are longest hold. Your first-ever set of an exercise is a baseline, not a record, and a record is announced once per session.
• Progression. When you complete a workout with every set of a strength exercise ticked, Rhino offers a small step up for next time: one weight step (2.5 kg or 5 lb) for loaded lifts, one more rep for bodyweight ones. Choose Apply or Keep as is; exercises you cut short are never bumped.

Finishing, or stopping early

• Complete workout. The button at the bottom of the screen turns green once every set is ticked. Tapping it logs the session (every set, with its weight and reps, plus how long the session took), offers a progression if you earned one, saves any edits into the workout, and returns you to the home screen.
• Finish early. If sets are still outstanding, the app asks first. Choosing Finish anyway saves the workout and logs the session as cut short (it still counts towards your streak, and the heatmap shades it by the sets you did).
• Stop without saving. The close button in the top left abandons the session. Nothing is logged and weight or rep changes made during the session are discarded (notes, added or removed sets, supersets and schedule changes are kept). The app asks you to confirm, and tells you how many ticked sets would go unlogged so you can choose Complete workout instead.

A session in which no set was ticked is not logged, whichever way you leave.

Editing a workout

Tap the edit icon in the workout screen’s app bar to switch to the editor. Here you can:

• Rename the workout. Tap the name at the top.
• Reorder exercises. Press and hold an exercise, then drag it into place.
• Rename or remove an exercise. Use the controls on its row. Removing asks for confirmation.
• Add an exercise. Tap Add, enter a name, choose Strength, Cardio or Timed, and set how many sets it has and the starting numbers.
• Link a superset. Tap the link icon on a row to pair it with the exercise below (see supersets).
• Schedule it. The row of weekday letters under the name marks the days this workout is planned for. On those days it is recommended first on the home screen.
• Ask Rhino to revise it. Tap Ask Rhino, pick a suggestion (“Easier on my knees”, “Make it harder”, “Add more back work”, “Shorter session”) or type your own request. Rhino rewrites the whole workout, keeping the progress on any exercise that stayed. You can cancel while it is thinking.

Tap Done (or the back arrow) to return to tracking. Any changes are saved into the workout at that point, so they are kept even if you then stop the session without completing it.

Sharing workouts

Press and hold a workout card on the home screen and choose Share. You get a QR code and a link, either of which hands the whole workout (its name, exercises, sets, reps and weights, notes and supersets) to someone else.

• Send the link. Copy link or the share sheet passes it to Messages, email or anywhere else. On an iPhone with Gym Buddy installed, opening the link jumps straight into the app and offers to add the workout. Without the app it opens a web page that shows the workout and links to the App Store.
• Show the QR code. Hold it up and let the other person scan it with their camera. It carries the same link.
• Receiving one. Open a shared link, or scan the code, then confirm to save the workout. It is added as a new workout; nothing you already have is overwritten, and you can rename or edit it afterwards.

The workout is packed into the link itself, in the part after the #, which browsers never send to a server. Nothing is uploaded, no copy is kept, and the link keeps working offline once someone has it, but equally, anyone who has the link has the workout, so share it as deliberately as any other message. Editing a workout after sharing does not change the links already sent; share it again to pass on the new version.

Strength, cardio and timed exercises

Rhino picks the type when it saves a plan, and you choose it when adding an exercise by hand. Cards, the set editor, the overview and session history all show each type in its own terms.

Asking Rhino

Rhino answers questions about training, technique, recovery and nutrition. Open the chat from the home screen for a general question, or from inside a workout when you want advice about the session you are in the middle of: Rhino is told the workout name, the exercises, and how many sets you have done.

Replies stream in as they are written and may include lists and tables. Rhino uses the units you chose in Settings and knows your name and gym equipment if you have entered them. You can stop a reply mid-stream with the cancel button in the input bar.

Progress, streaks and the heatmap

Tap the streak banner on the home screen to open Progress.

Streaks

• A streak is a run of consecutive calendar days with at least one logged session.
• A day you have not trained yet does not break a streak. If you trained yesterday, the banner shows the streak and asks you to train today to keep it going. Miss a whole day and it resets.
• Best streak is the longest run anywhere in your history. This week counts sessions since Monday. Total sessions counts everything logged.

Activity heatmap

The heatmap is a calendar of the last few months, one square per day, with weeks in columns. A square is shaded by the number of sets you completed that day, relative to your own typical session: an ordinary workout is mid-shade, one you cut short is lighter, and a day well above your usual (two sessions, say) is darkest. Tap a square to see which workouts you did that day, then a session to see every set with its weight and reps, how long it took and the volume moved.

Sharing a session

The share icon on a session opens a preview card (workout, date, sets, time, volume and your best set of each exercise) that Share image sends as a picture to Messages, Instagram or anywhere else the iOS share sheet reaches.

Personal records

Below the heatmap, every exercise you have logged is listed with its heaviest set and estimated one-rep max (longest distance or hold for cardio and timed work) and the date you set it. Long lists collapse behind Show all.

Body weight

Tap Log to record today’s weight in your unit. The card shows the latest reading, the change over the last month and a small trend line. One reading is kept per day; logging again replaces it.

Settings, units and your gym

Open Settings from the gear on the home screen.

• Name. Optional; Rhino uses it now and then.
• Units. Metric (kg, km) or imperial (lb, miles). Everything is stored in metric and converted for display, so you can switch at any time without losing anything.
• Rest timer. Off, 60, 90, 120 or 180 seconds.
• Haptics. Turn off the taps and buzzes.
• Apple Health. Off by default. When on, Gym Buddy asks Health for access, then saves each completed workout (as a strength, cardio or core-training workout depending on what the session mostly was) and reads your heart rate while a workout is open. Sessions of under a minute, or stopped without completing, are not saved. The heart rate is whatever is writing to Health at the time: an Apple Watch, a Bluetooth strap, or AirPods Pro 3 on iOS 26 or later. Live beats per minute appear beside the set count, and the average and peak are kept on the session in Progress. Gym Buddy never reads any other Health data.
• My gym. The equipment you have access to. Type a name, or tap the camera to photograph a machine and let Rhino identify it (the photo is sent to the server for that one request and not stored). Rhino only prescribes exercises you have kit for.
• Export sessions. Shares a CSV of every logged session, one row per set with date, workout, exercise, type, weight, reps, distance and time, for a spreadsheet or another app.
• Delete all data. Removes workouts, history and body-weight readings from the phone. Settings are kept.

Deleting a workout

Swipe a workout card on the home screen from right to left and confirm. The workout is removed from the phone. Past sessions of it stay in your history, so your streak and heatmap are unaffected.

Connectivity

Rhino runs on a server operated by the developer. Creating a workout, revising one and chatting all need an internet connection; everything else works offline. Requests are sent over HTTPS. Replies for a full workout can take a little while; the typing indicator shows the request is in progress, and you can cancel it at any time.

Troubleshooting

Rhino does not reply, or the request fails

Check that the phone has an internet connection and try again. If the server is busy, a request may time out after about a minute; sending it again usually works.

“Could not save the workout”

Rhino’s plan could not be converted into a structured workout. Ask Rhino to present the workout as a table of exercises, sets, reps and weights, then tap Save again.

The recommended workout is not the one I expected

A workout scheduled for today is recommended first. Otherwise the app recommends the saved workout that was completed longest ago; completing a workout moves it to the back of the queue.

No “last time” line or records appear

Both are built from logged sessions, so they appear from the second time you complete an exercise. Exercise names are matched ignoring case and spacing; a renamed exercise starts a fresh history.

The rest timer does not start

Check it is not set to Off in Settings. It also does not run after a set of an exercise that leads a superset, or after the last set of the workout.

My streak reset

A streak needs a logged session on every calendar day. Sessions are logged only when you complete a workout (including finishing early) with at least one set ticked. Stopping with the close button does not log a session.

I want to move my data to a new phone

Workouts and history live only on the device. They are included in an encrypted iCloud or computer backup of the phone and restored with it. Settings also offers a CSV export of your session history.

Known limitations

• iPhone only, portrait only. There is no iPad layout or Apple Watch app.
• Heart rate needs a sensor that writes to Apple Health; the phone itself has none. AirPods Pro 3 heart rate needs iOS 26.
• History exports as CSV; there is no sync between devices.
• Rhino needs an internet connection and the developer’s server to be running.

Privacy in brief

• No account, no analytics, no advertising, no tracking.
• Workouts and session history are stored on the phone only.
• The text of your conversations with Rhino (and, for in-workout chat, the workout it relates to), your unit preference, and any name or equipment list you have entered are sent to the developer’s server to generate the reply. A photo taken to identify equipment is sent for that request only. Do not include personal or medical details you would not want sent.

The full privacy policy has the detail.

Support

Questions, bug reports and suggestions: support. Please include your iPhone model and iOS version for bug reports.