● For iPhone and Apple Watch

Your new training notebook.

The promise: no account, no ads, no subscriptions.

A workout log that lives on your phone, backs up to your own iCloud, and works fully offline. Exportable any time. Yours, forever.

status: coming soon · beta testing July–August 2026
the sign-up link will land right here. Stay tuned.
Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts. Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts. Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts. Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts. Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts. Delta's home screen: a four-tile dashboard showing workouts, a rolling week, week streak, and cardio miles, above the daily check-in and recent workouts.
fig. 01 · the dashboard, four tiles of your choosing

Goal one

Faster than paper.

Every set arrives prefilled from the last time you did that lift. A normal day is lift, lock in, rest: one tap commits the set and starts the rest timer. The weight lights up when you beat last session, and PR badges land on the set that earned them.

programs · percent training

Programs that wave

Multi-day plans with per-week percent and rep targets. When a cycle completes, Delta asks about new top weights. You decide, per lift, every time. Delta never changes a weight on its own.

watch · live HR · pause

The wrist runs the workout

The watch runner steps through your plan set by set with live heart rate. Lock in from either device. Pause when life interrupts; paused time never counts as training time.

cardio · HIIT · bluetooth

Strength first, cardio honest

GPS runs with routes, heart-rate zones, Bluetooth machines streaming straight into the log, and HIIT that taps your wrist at every interval switch.

On the wrist

Leave the phone in the bag.

Start a program day and the watch walks it: the set you are on, the weight, the target, live heart rate, and the rest clock. Turn the crown when you got more reps than planned, lock in, lift. The phone stays in sync either way, and if life interrupts, pause from the wrist.

Delta on Apple Watch mid-workout: Back Squat, 305 by 5, set 3 of 15, live heart rate 61, rest timer at 27 seconds, a crown-adjustable rep count, and a Lock In button.
fig. 02 · set 3 of 15, next set queued

The differentiator

Insights that observe, never coach.

Plateau detection, readiness signals, training cadence: every insight is a fact derived from your own log, stated with its evidence. Each one stays silent until there is enough data to be honest, and none of them will ever tell you what to do.

Overhead Press: top weight stuck at 115 lb for 4 sessions without hitting the rep target. Linear progression conventionally prescribes a ~10% deload; that is a convention, not a command. An observation from your logged data, not coaching advice.
Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar. Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar. Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar. Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar. Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar. Delta's Progress screen: weekly consistency and a readiness correlation up top, then a grid of lifts with sparklines, the rolling cardio total, and the time-in-zone bar.
fig. 03 · lifts, cardio, time in zone
One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight. One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight. One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight. One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight. One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight. One lift drilled in: Back Squat top weight and estimated 1RM charted together, deltas versus last session, a measured progress rate in pounds per month, and strength relative to bodyweight.
fig. 04 · one lift, two estimates
An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below. An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below. An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below. An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below. An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below. An outdoor run's detail: the route drawn on a park map, named Piedmont loop, 3 laps with a best lap time, and the heart-rate chart with time-in-zone below.
fig. 05 · one route, named, lap-aware

Your data

Bring your history. Take it with you.

Import your training history from other lifting apps (major export formats import directly), or fill in the paper template with any spreadsheet; your old PRs are first-class citizens in minutes. Export everything as CSV whenever you like. The file is yours to keep, graph, or leave in a drawer.

The filter

Not for everyone. On purpose.

Try a theme the screenshots switch too · no scripts were harmed (there are none)
Privacy label: Data Not Collected.

Delta has no account system, no analytics, no tracking, and no servers. Your log syncs through your own private iCloud; the developer cannot read it. This is not a policy that could change. It is an architecture. Read the whole policy; it is short, because there is very little to say.