SET THE CONTEXT
Goals, time and equipment
Choose strength, hypertrophy or powerbuilding. Flux builds around the days, minutes and kit you actually have.
ADAPTIVE WORKOUT PLANNER FOR IPHONE & IPAD
Your training.
All coming together.
A plan built around you. Every set ready to train. A clearer view of what’s working. Flux brings your workouts, progress and recovery together on iPhone and iPad.
Download free. Try every feature for 14 days with no payment, subscription or automatic charge. After the trial, keep training with one Lifetime Unlock. Eligible existing paid owners keep Full Access.
- Get started
- 14 days of Full Access
- Make it yours
- Light, Dark or System
- Privacy
- On-device ML
Light or Dark. Always Flux.
HOW FLUX WORKS
One continuous training loop.
Not another plan to manage.
You bring the intent and effort. Flux handles the repetitive programming decisions that normally live in notes, spreadsheets and guesswork.
TRAIN & RECORD
Every useful signal captured
Log load, reps and effort. Finish offline: completion confirms once your workout and final feedback save on your device.
ADAPT THE PLAN
The next session gets smarter
Performance, feedback and recovery context shape what changes next—without taking control away from you.
THE BENEFIT
Open the app and know what to do, why it fits today and what progress looks like next.
BUILT BEYOND THE LOGBOOK
From your first plan
to your next step forward.
Less waiting, clearer progress and individual set targets. Discover Light mode and the latest improvements in Flux 8.6.0 →
01 · YOUR PLAN
A plan built around you
Build a routine around your goals, equipment and schedule, with strength and HIIT in the same plan.
02 · YOUR SESSION
Every target ready before you train
Walk in knowing your exercises, weights, reps and rest. Review the session and make supported edits before your first set.
03 · YOUR PROGRESS
Progress you can understand
See what changed, which exercises contributed and when Flux needs more evidence. Follow Performance, Health and Routine in Insights.
YOUR DASHBOARD, YOUR WAY
The details that matter.
Right where you need them.
Choose and arrange widgets inside Flux to keep your routine, training calendar and personal metrics in view.
01 · ROUTINE OVERVIEW
Know what’s next
Follow your programme’s current phase, session progress and next milestone without leaving your Dashboard.
02 · TRAINING CALENDAR
See your consistency
Keep completed workouts visible in a monthly calendar. A simple view of the training you’re putting in.
03 · CUSTOM KPI
Keep your metrics close
Choose a Custom KPI and compare trends over time. Here, body fat and recorded sleep sit side by side.
Dashboard widgets shown in Dark. You can also choose Light or follow your device’s appearance with System.
Explore more of FluxWHY FLUX
More adaptive than a plan.
More useful than a tracker.
A practical comparison of common training tools. Individual products vary; the difference is whether planning, performance and recovery work together.
| What you need | Static plan | Basic tracker | Chat-based apps | Flux |
|---|---|---|---|---|
| A complete workout in seconds | Pre-written | — | Yes | Yes |
| Uses your training history | — | Stores it | If re-entered | Continuously |
| Progresses load and reps | Fixed rules | You decide | One-off advice | Session to session |
| Accounts for recovery | — | — | If prompted | In the plan |
| Fits your equipment and time | Sometimes | Manual edits | Yes | Every session |
| Keeps you in control | Follow or abandon | Yes | Regenerate | Edit, swap, override |
“Chat-based apps” means a general fitness chatbot or one-off generated workout—not an integrated training log with on-device machine learning built from your history.
PRIVATE BY DESIGN
Smart training.
Not a chatbot.
Flux is not ChatGPT for the gym. Personalisation runs through on-device machine learning trained on your workouts—not cloud AI agents or open-ended chat prompts.
ON-DEVICE ML
Personalisation stays on your iPhone or iPad
Exercise selection, progression, and readiness use machine learning models that run locally. No need to paste workouts into a chat window.
YOUR DATA
Optional sync. No selling health data.
Workout history can stay on-device. Cloud sync is optional for signed-in backup. Apple Health integration is user-controlled. See our privacy policy.
SECURITY
Built for training, not engagement loops
Flux adapts from logged performance and recovery signals you choose to share—not from open-ended AI conversations or third-party data brokers.
WHAT CHANGES FOR YOU
Fewer programming chores.
Better training decisions.
ARRIVE WITH A PLAN
Stop building every session from scratch
Your next workout is ready around your goal, schedule and gym—not copied from somebody else’s week.
PROGRESS WITH CONTEXT
Know when to add, hold or ease off
Flux connects performance and recovery so progressive overload becomes a decision, not a reflex.
KEEP THE FLEXIBILITY
Adapt without derailing the programme
Swap exercises, change equipment or run an ad-hoc session while your longer-term training stays coherent.
SEE THE PLAN
Your routine, easier to navigate
Overview brings workouts and progress together. Settings keeps controls close. Supported saved programmes also include a Guide.
FREE TO TRY. NO SUBSCRIPTIONS.
Try every feature.
Keep it with Lifetime.
Start with a 14-day Full Access trial managed by Flux. It requires no payment and never charges you automatically. After the trial, training requires a Lifetime Unlock or an eligible existing entitlement.
FULL ACCESS TRIAL14 DAYS
Get to know the complete app
- Free download for iPhone and iPad
- Every feature available during the trial
- No payment required to start
- No subscription or automatic charge
- Adaptive workouts, routines and insights
- Training access ends when the trial expires unless you have an unlock
LIFETIME UNLOCKPAY ONCE
Keep Full Access for life
- One non-consumable in-app purchase
- Permanent access to every training feature
- No monthly or yearly recurring fee
- Apple shows your local price before you confirm
- Eligible existing paid owners and recognised historical purchasers keep Full Access
- Lifetime and Founder Lifetime holders do not need to buy again
TRAINING, EXPLAINED
The Flux Workouts blog.
Keep the science useful.
Practical guides, product releases and the decisions behind better strength training.
Workout Plans · 20 Sept 2026
Best 4-Day Workout Split for Strength and Muscle
Upper/lower four days a week is the default for most people. A worked week, when to use PHUL, and why four-day PPL is usually the wrong shape.
Read article → Progression · 20 Sept 2026
What to Do When Your Lifts Stall
A stall is several hard sessions, not one bad day. Hold the load, check recovery, then change one thing — with a four-week squat example.
Read article → Flux Updates · 30 Sept 2026
Flux 8.8.1: Clearer targets, more room to progress
Optional Dynamic Targets, clearer set previews and better progression and recovery guidance. See what Flux 8.8.1 changes in your next workout.
Read article →YOUR NEXT SESSION IS THE START
Train with a plan that
keeps up with you.
Download free and try every feature for 14 days. No payment, subscription or automatic charge. After the trial, keep training with a one-time Lifetime Unlock—or your eligible existing access.
iPhone & iPad · 14-day trial · One-time Lifetime Unlock