An iPhone app by Mission Built
Fueling is training. A meal timing tracker for people who train. Your session doesn't move. Your meals do.
Why it exists
I sat in a nutrition seminar at the Shaw Strength Summit and heard Nathan Payton say it plainly: if you are not eating properly, you are failing your training. Eating is part of your training.
That sent me home to rebuild how I eat, and then looking for an app that understood it. The meal-timer apps are alarm clocks. The routine apps roll a late morning into the session. The macro trackers know what I ate to the gram and have no opinion about when. Not one of them asks what time you train. So I built the one I needed. Four ideas hold up everything it does.
What it does differently
Timing · Protect the session
The day is anchored to the session, not the clock.
The carb surge, the fuel around the session and the meals after it are tied to the session. Everything before them is worked out from the time you actually ate. A late morning tightens the gaps and says what moved; it never pushes the carb surge past the start of the session.
Other apps: Alarms every N hours, or routines that roll lateness forward into the session.
Macros · Protect the protein
Weighed from the plate, or typed. Never both.
A meal is a list of ingredients and quantities, so the numbers come from the ingredients and editing a portion moves them. The daily target lives apart from the plan, so the editor can say "this plate puts the day 40 g of carbs over" while you are still building it.
Other apps: A food database and a total. No plan to measure the plate against.
Logging · Protect the record
Log when you eat, not when it was due.
The sheet opens on now with 15, 30 and 60 minutes ago one tap away, and shows what every remaining meal does at that time before you commit. Move today's session from the Today screen and the meals tied to it move with it.
Other apps: "Done" means now, so the day keys off the wrong number.
Travel · Protect the day
Home or Away, in one tap.
Flip Travel on Today, or let the app do it when you are far from home. With IronStack on the phone, it is one switch for both apps. Skip a meal and it stays a decision, not a miss. History compares home days to travel days.
Other apps: One schedule, and it assumes you are home.
Surfaces · Protect the protein
You should rarely have to open it.
Notifications carry the plate and two actions: "Log it" and "Not yet · 20 min". Home and Lock Screen widgets with a live countdown. A card on the Lock Screen from an hour before each meal to thirty minutes after, with a Log button on it and at the top of the screen.
Other apps: A badge, and a screen you unlock to answer it.
Stack AI · Protect the day
An AI that proposes. You decide.
Turn it on and let Stack AI build the plan, or send it the plan your coach wrote, as a photo or a PDF, and it brings it in for you to review. Ask for targets and a fixed formula does the arithmetic, not the model. Eating out, hand it up to five menu photos, a link or a restaurant name, and it fits options to this meal's numbers. Nothing changes until you tap a card. Not a doctor, and it says so before you ask.
Other apps: A chatbot that talks, or an AI that edits your plan without asking.
How you use it
Just the times, your coach's plan, let Stack AI build it, or build it yourself; or see a finished day first. Just the times builds a working day from when you eat and train, no AI and no account: the morning meals follow one another from your first meal, the carb surge before the session and everything after it are tied to the session. Five meals by default; change the number in Settings. Put food on the plates when you are ready, or let Stack AI fill them.
One tap for now, one for thirty minutes ago. The sheet shows what every remaining meal does before you commit, and the notification can log it without opening the app. The carb surge holds. The rest of the day bends around you.
Client lunch, airport, empty fridge. Send Stack AI the menu, a link or what is in the kitchen and it fits an order to this meal's numbers. Nothing changes until you tap. History keeps score, so you can see what the road does to you.
Meals are plates. Fuel is what you take for the session rather than as a meal: pre-workout, the jug you sip through the session, the shake after it, electrolytes, creatine, water. It can carry protein, carbs and fat, and those count toward the day's totals. Fuel is never a meal: it isn't in the meal count, doesn't move the meals around it, and isn't scored for timing. It gets its own alert and its own line on the record. Three shelves on the Plan tab: stacks, meals, and ingredients (about two hundred built in, plus your own, entered like the label). Drop a saved meal onto any plate. Apple Health gets the macros at the real eat time; if you allow it, the app shows what other apps logged (never added to yours) and offers your weight. Light and dark. History that scores against the target you set. Your plan is a file on your phone. No account, no sign-in, no cloud sync.
Side by side
The fine print, in plain words
The code
Closed app. Open data.
MealStack is a closed-source app from Mission Built. What is open is your data: a plan is a plain JSON file in a documented format, the MealStack Schema. Plans and stacks export as those files and import back in. The MealStack name and the marks stay with Mission Built.
Price
Pricing coming soon.
Every app has a free way in, plus paid plans. Every Stack AI question runs on a server I pay for, so Stack AI is part of what the paid plans cover. The prices land here before they land in the store.
Your data
On your phone. Two switches.
The plan, the log and the day never leave the phone. Stack AI is off until you turn it on; nothing goes to Anthropic until you do, and then only when you ask. What you send it goes to a server Mission Built runs, and it is metered. Turn it off in Settings › Stack AI any time. Usage data is a second switch the app asks about once. The privacy page says exactly what, where, and for how long.
Not a doctor. Neither is Stack AI.
I am not a doctor or a dietitian, and nothing on this page or in the app is advice about how you should eat. It is how I manage my own diet. Stack AI is an AI, can be wrong, and is not one either: its targets are estimates from a formula you can read, it declines questions about medical conditions, medication, pregnancy and supplement doses, and it points you to a professional instead. Nothing it proposes changes your plan until you tap.
Join the beta
Newest build: MealStack 0.9.1 · Build 94
MealStack runs my own day, every day, and a small group of outside testers is on it with me. I add testers by hand, in small batches, from the email on your Apple ID. You get an invite from Apple, a link to install, a choice of how to start, and a short list of things I would like you to break.
Each beta build lasts ninety days, and the next one arrives before it runs out. The address is used for the invite and nothing else; you can leave from the invite email at any time.
The form is not taking names right now. Email support@missionbuilt.io with the address on your Apple ID and I will add you by hand.
By invite, from the form. Small batches, added by hand.
The public door, published by Mission Built.
For testers
Terms of use (a draft, under review) · Privacy · Support · Acknowledgements
Questions
Better together
MealStack times the fuel. IronStack keeps the record of the work it fuels. Each one stands on its own, and neither will ever ask you to install the other. Put both on one phone and they start talking about the same person.
MealStack
What you ate
Apple Health
Food and workouts, one timeline
Shelf on your phone
Travel · workout start · workout end
IronStack
What you lifted
Both apps to Apple Health
In both apps todayCarries MealStack writes protein, carbs, fat and calories at the time you actually ate. IronStack writes the workout as strength training, if you switch it on.
Food and training on one timeline in Health, from two apps that never had to know about each other.
Either app to Both apps
In both apps todayCarries Home or Away, which app flipped it, and when the trip started. A few bytes in a shelf on the phone that only Mission Built apps can open.
Land in Denver, flip it once, or let either app do it when you are far from home. MealStack plans the day for the road; IronStack counts the workout in a strange gym toward Road Warrior.
Either app to Both apps
In both apps todayCarries Today's session time, when you move it in either app.
Move today's workout in IronStack and MealStack says so the next time you open it: Sync to the new time, or Skip. It works the other way too. Neither moves the other by itself.
IronStack to MealStack
In both apps todayCarries When today's workout started and when it ended.
The shake after the session is called when you finish, not at an hour picked in advance, and the meals after it re-time on the real end. Switch on "IronStack times my after-session meals" in MealStack.
Both apps to Both apps
In both apps todayCarries Whether you trained and ate to plan on the same day.
Double Stacked in both apps, for the days both did their job. In MealStack, Fuelled and Stacked for a carb surge before a workout IronStack logged, and Straight off the bar for a shake on time after one.
IronStack to MealStack
IronStack today · MealStack soonCarries When your workouts usually start, by weekday, worked out from your own log.
MealStack anchors the carb surge to the hour you really lift on a Saturday, without you typing it in.
Both apps to Your files
IronStack today · MealStack soonCarries The Mission Built Schema: one documented, versioned vocabulary. A workout reads like a meal, a program like a plan, a session like a day.
Export from both and a single script or spreadsheet reads the lot. Your data outlives either app.
Either app to Stack AI in both
ComingCarries Bodyweight, height, age and goal, the details Stack AI needs for a target.
Tell Stack AI once, in either app. The other already knows.
"IronStack ready" means IronStack's half is built and waiting, and MealStack reading it is next on MealStack's list. Installing both turns nothing on that you have not said yes to.
The rules that outrank the features
Also on the Rack
Protein · Session · Day · Record
Fueling is training.