Is Base available on the App Store?

Yes. Base is on the App Store for iOS 17 and later, and it is free. There is no invitation, no TestFlight and no payment. Android is not released yet; there is a list on the download page for that.

What do I need to use Base?

An iPhone running iOS 17 or later, or an Android device with Health Connect. A wearable is not required but changes the experience substantially, without one you get manual logging and adaptive maintenance, with one you additionally get recovery scoring, sleep scoring and automatic endurance session matching.

Will my data carry over between builds?

Yes. Your log syncs to a private database under your account, so it survives reinstalls, device changes and every update. Progress photos are the exception: they are never uploaded, and are archived instead to an album in your own photo library so a reinstall cannot lose them. The one feature that reads them is the optional body fat estimator, which is off by default.

Does Base cost anything?

No. Base is free on the App Store today. If that ever changes it will be stated plainly on this page and nowhere else first.

Download Base: The Hybrid Training App for iOS

Android is not out yet. It is built and it runs, but it is not released, so the list on this page is the place to be told when it is.

What you need

Requirement	Detail
iOS	17 or later. The health integration needs a native module, so this is not a web app or an Expo Go build
Android	A device with Health Connect available
Wearable	Optional but substantial. Apple Watch, Garmin, Whoop, Oura, Fitbit and Polar all reach Base through the platform health store
Account	Email and password. The log syncs so losing the phone does not lose the history

Without a wearable you get: manual logging, adaptive maintenance from weight and intake, endurance prescriptions from a manually entered threshold, and the full weekly check-in.

With one you additionally get: recovery scoring from HRV and resting heart rate against your own baselines, sleep scoring, a calorie target that moves as you move through the day, and endurance sessions matched and graded automatically from the watch's own record.

What is in the build

The daily loop: bodyweight, day-template food logging, set logging with reps in reserve, automatic endurance session matching
Adaptive maintenance measured from your own trend weight and intake
A calorie target built on what this day actually costs rather than a figure committed last Monday
Endurance prescription and grading from your own threshold pace or FTP, with per-rep, time-in-zone and average grading depending on what evidence the session left behind
Acute-to-chronic ramp rate on endurance minutes
Recovery and sleep scoring against your own thirty-day baselines, with an explicit "building baseline" state rather than a fake number
Readiness: a RIR offset for today's session and a reactive deload trigger
Eighteen tracked micronutrients with explicit coverage reporting
Progress photos archived to your own photo library
The generated weekly check-in, copyable as plain text
A plain-English explanation behind every derived number

What is still rough

Stating this is more useful than not.

Fractional set volume per muscle per week is not yet a first-class screen. The data is there; the view that makes it the primary progression signal is not finished. It is the largest single gap against the protocol the app is built on.
Protein distribution across meals is not tracked. Total protein is; the per-meal split that actually determines the response is not.
Swimming is not a supported endurance discipline. Run and ride are. A triathlete gets two of three.
The AI features have a daily limit. The scanner, the coaches and the chat run on a free daily allowance of AI use per account, which covers a normal day. Past it, they pause until the next day unless you add your own Gemini API key, which has no limit.
There is no Android watch companion. Health Connect gives Base the data; it does not give it a watch face.

What you are signing up for

Version one, which means bugs. Base does record which screens are opened and when something fails, which helps find the obvious breakages, but it records nothing about what you actually logged, so a wrong number or a confusing screen is invisible to it. Say so when you hit one. There is no crash reporter attaching your stack traces either; the analytics counts that a screen threw, not what it was showing.

Your data is safe across updates. The log syncs to a private database under your account with row-level security, so it survives reinstalls, device changes and every release. Progress photos never sync and are archived to your own photo library instead, so a reinstall cannot lose them either. The full disclosure is on the privacy page.

What to do next

If this is the app you want, get it on the App Store. It is free, and it is iOS 17 and later. On Android, leave an address and you get one email when the build is out.

If you have not read what hybrid training is or how Base works, those two pages will tell you within five minutes whether this app is built for the problem you actually have. It is a narrow tool and it is better to find that out before installing.