Your AI plans it.
Parameter runs it.
Ask for a week of training and it appears on your phone and watch, ready to run. Afterward your AI reads the set-by-set logs, effort ratings, notes, and heart-rate data, and adjusts next week. Works with Claude, ChatGPT, Gemini, Grok, Perplexity, and any MCP client.
Plans arrive on phone and watch, ready to run. Real app components shown.
The whole workout, run from the wrist.
The watch app is fully independent. Leave the phone at home and nothing is missing. When both devices are present, they mirror live and either one is the remote. Check off a set on the watch and the phone responds, even when the phone is locked.
Live heart rate, colored by zone. Segments advance themselves.
Check off sets from the wrist. The phone stays in the bag.
Rest timers count down on the wrist and tap you when it's time.
Crown adjustments
Turn the crown to adjust a load or a speed mid-set.
A haptic vocabulary
Each event has its own tap. You learn them in a workout or two.
Either device leads
Pause on the watch, resume on the phone. Both stay right.
Rate it from the wrist
Effort rating and notes right after the workout ends.
One plan. One history. Stop stacking two apps.
Five workout types, all first-class: intervals, strength routines, cardio sessions, external classes, and real rest days with active-recovery guidance instead of an empty gap. Your AI sees all of it.
Strength, with the details that matter.
Straight sets, supersets, and circuits run as a block-by-block checklist. Nothing to type mid-workout unless something changed.
Previous performance sits under every set. The only question you have mid-workout, answered where you're looking.
Did it as planned? Check. Did something else? Adjust, then check. Both take seconds.
Starts itself after each set. Background the app and the rest-over notification can log the next set, or adjust it, without reopening the app.
Rack's taken? Swap the exercise mid-workout from curated suggestions. The deviation is logged, so your AI knows.
The plate calculator knows your rack.
Tell it once which plates you actually own. From then on, every target load becomes a per-side breakdown of your real inventory, not a textbook gym's.
When the exact number can't be built, it says so and offers the nearest loads you can, just below and just above. No mental math at the bar.
Intervals, executed exactly.
The current segment fills the screen: what you're doing, at what target, for how much longer. You never wonder where you are in the workout.
Segments change themselves, each with a distinct sound and haptic. A 5-4-3-2-1 countdown leads every transition.
The next segment previews before it arrives, so the change of pace is never a surprise.
Too hot, too easy? Adjust the target mid-segment. The change is recorded as a deviation, not papered over.
If your heart rate drifts out of the target zone, a calm amber banner says so. No alarms, no shouting.
Cardio and sport sessions.
Runs, swims, and walks get a target and a timer. Open sport sessions, like basketball and friends, run with live heart rate and Z1 to Z5 zone targets from your profile.
Keep doing your favorite online classes.
Parameter deep-links into Peloton and many other class apps, and the finished HealthKit workout imports into your Parameter history like any other completed workout, where your AI can see it. One plan, one history: your Tuesday class counts.
Parameter sets the treadmill. You just run.
On Bluetooth FTMS treadmills, bikes, and rowers, Parameter pushes each segment's speed, incline, resistance, or power to the machine and verifies every setpoint took. Ask for stay-in-zone and it eases the machine up and down to hold your heart rate there. No competitor pairs this with AI planning. The machine will feed distance and other metrics back to your phone and watch,
You keep control of the console. Nudge the speed yourself and Parameter follows your override and logs it. It never fights you.
Parameter never starts or stops the machine. The belt moves when you say so, full stop.
Your wrist heart rate can broadcast to many consoles' chest-strap pairing menus, so the machine's own display shows your number.
Works with FTMS-compatible machines. HR broadcast pairs with many consoles, not every one.
No smart machine? Key it in.
For machines Parameter can't control, any interval workout flattens into a numbered step table: step, time, speed, incline. Prop the phone on the console, key in each step as it comes, and go.
It works with many machines that can't be controlled by Bluetooth, including the hotel's.
Planned next to actual. Always both.
Every deviation records itself: changed reps, an adjusted speed, a substituted exercise. The detail view shows the plan and what actually happened, side by side, not to judge you, but so your AI can plan better moving forward.
Say "left knee felt off on set three" mid-workout. The note timestamps itself to that set, and your AI reads it later.
Remembered something later? Add a note to the finished workout, or to any single set or interval in it, and your AI reads it with the rest.
Full JSON and CSV export. Free, forever. Export paywalls are a category sin we don't commit.
A skipped workout is gray, not red.
"Not done" is a fact, not a failure. There are no streaks to break, no flames to keep lit, and no re-engagement notifications, ever. Notifications do four jobs: morning summary, workout reminders, rest timers, and check-ins. None of them is marketing.
Sick, injured, traveling? One tap sets your status. Reminders pause, the tone softens, and your AI will plan around it.
Taking it easy. Your AI will see this next time it plans.
Real app components. Gray means not done. That's the whole event.
The depth is there when you want it.
Live Activity
Elapsed time and current segment on the lock screen and Dynamic Island, with Pause and End.
Widgets everywhere
Home screen, lock screen, watch complications, Smart Stack.
Siri and Shortcuts
Start, skip, log effort, or set status by voice. The Ultra's Action Button starts your workout.
Manual builders
Full interval and strength builders, templates, copy and repeat. Complete without an AI.
Exercise catalog
510 exercises, 708 aliases, substitution suggestions, custom entries.
Equipment catalog
About 140 equipment types, plate and dumbbell inventories, per-machine click increments.
Heart-rate zones
Z1 to Z5 from your profile, hand-editable, with drift alerts. Not a paid upgrade.
History and trends
Weekly volume, effort trend, estimated 1RM, adherence. Filterable log.
Never loses a set
Every check-off is saved before the screen advances. A crash never costs you a workout.
Auto-pause, politely
Stillness detection asks before pausing and never auto-ends. Overtime gets a "still going?" check-in.
Status system
Sick, injured, traveling, on break. One tap, and everything adapts.
Swim-ready
Water lock engages itself for swim workouts.
HealthKit
Reads and writes, both directions. Your rings still close.
Free full export
One zip, complete JSON, CSV, and a plain-language README.
Pure SwiftUI
Zero third-party SDKs. No ads, no analytics, no noise.
What's coming after launch.
Everything on the list, in no promised order. If one of these matters to you, say so at [email protected] and it moves up.
Zone hold on more machines
The heart-rate zone loop today adjusts treadmill speed and indoor bike power. Rowers, cross-trainers, stair climbers, and resistance-based bikes are next.
Custom equipment
Gear the catalog doesn't know yet, added by name, the way custom exercises already work.
Band resistance levels
Tell Parameter how strong each band you own is, whether the set is labeled in pounds or as light through extra heavy. Your AI can then pick the right band instead of guessing at it.
Warm-up and cool-down phases
Cardio sessions with easy minutes built in on both ends, and common stretches in the exercise list.
Quick start
Pick an activity and go. No goals, no setup. It lands in your history when you finish.
AMRAP sets
As many reps as possible, timed or to failure, recording what you actually did. Timed sets get a countdown that logs itself.
Share with a friend
Let someone you trust see your training data, so their AI can write your programming instead of yours.
Choose your watch metrics
An extra page during watch workouts showing a grid of the numbers you pick, set per activity.
Pace and metrics read aloud
Hear your pace, distance, or heart rate called out as you move, at an interval you choose, so you can keep going without looking at anything.
Richer exercise catalog
Demonstration media and muscle groups for every exercise, plus matching for your own historical exercise names.
Notes your AI can update
Your AI keeps its own planning notes on your profile, like a coach's notebook. Everything else stays read-only, always.
Heart rate for every interval
Average, highest, and lowest heart rate for each segment of an interval workout, not just for the session as a whole.
Heart rate without an Apple Watch
Pair a Bluetooth chest strap, or a watch that broadcasts its heart rate, and the live readout and zone alerts work with no Apple Watch involved.
Max effort segments
A segment whose target is everything you have left, with no number to hold and nothing steering a machine.
Effort as a goal
Set how hard a session should feel, on the same scale you use to rate it afterwards.
Calories as a goal
Set a session's target as the energy you want to burn, then see it against what you actually burned.
More ways to train
A pass through every activity to cover the way people actually train, like tempo lifts that time each part of the rep.
Bring your history with you
Import training from other apps and file exports, with enough detail that your AI can program from it.
Pick your activities
Tell Parameter which activities belong in your plan, so your AI programs what you want and skips what you don't.
Faster pace on the phone
Phone workouts pick up distance and pace sooner by reading your steps alongside GPS, the way the watch already does.
Warm-up sets, worked out for you
Tell Parameter your working weight and it builds the ramp up to it, loaded with the plates you actually own.
Load the bar during your rest
The rest timer links straight to the plate calculator for the set that comes next, so you can change the plates while you wait rather than after.
Plate calculator on the watch
Work out what to load from your wrist, without reaching for your phone.
Ask Siri to be your trainer
Siri can plan and adjust your training too, by voice or in text, with no separate AI to connect. Included with the AI connection.
iPad and Mac
Review your week, dig through your history, and build routines on a bigger screen with a keyboard. Workouts still run on iPhone and Apple Watch.
Your usual activity, remembered
New workouts start on the activity you pick most often instead of asking every time.
Spanish, if people ask for it
The app, the watch, and this site in Spanish. Listed as a maybe rather than a plan, because it only happens if there is real demand for it.
Android, if people ask for it
Parameter is iPhone and Apple Watch today. An Android version is a genuine possibility and not a commitment, and the same rule applies. It only happens if enough people want one.
The roadmap comes from beta testers and early users. No dates, because honest ones are impossible this early.
A fitness tracker you'd keep even without the AI.
With it, a coach.
The beta is open on TestFlight. Join the beta
See how the AI connection worksFree to use. The AI connection is $1/month.