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Why Ferrabelle Pro is a one-time purchase, not a subscription

By Chris Ayers 5 min read

Ferrabelle is free. There is an optional Pro unlock for USD 9.99, paid once. No subscription, no ads, no account. People tend to assume there must be a catch, so here is the reasoning.

What you pay for once

The free app includes cycle tracking with predictions, the daily Fe Score, Health Connect import, encrypted backups and export. That is the whole core, and it is not a trial. Nothing in it expires.

Pro adds the training forecast, Fe Score history, the insights overlay, the AI assistant, workout suggestions and personal findings, training blocks, the monthly recap card, partner messages, coach share and the doctor report. It costs USD 9.99 and you pay it once. Until October 2026 it was USD 4.99. Google Play shows the price in your own currency, and in some countries it is set lower.

In Google Play’s terms this is a one-time product. Google’s own developer documentation describes it: “a one-time product is a single transaction that grants access to the purchased content permanently”. The kind Ferrabelle uses is non-consumable, which Google describes as products that “are purchased once and provide a permanent benefit”, with “premium upgrades” as its example. Google contrasts them with subscriptions, “which involve recurring payments”. So the promise is not only mine. It is how the product is registered with the store.

Why there is no subscription to pass on

Many apps charge monthly because they have monthly costs. Servers, databases, sync, accounts, analytics, and support for all of it. A subscription is a reasonable way to pay a bill that arrives every month. I do not think it is a dishonest model. It is the right model for a product with recurring costs.

Ferrabelle does not have that bill. Everything you log lives on your phone. There is no Ferrabelle account and no Ferrabelle server. Predictions run on the phone. Backups are encrypted on the phone and saved wherever you choose. The AI assistant, if you turn it on, runs on your phone or, if you choose, through a provider you pick under your own account. When you buy Pro, Google Play handles the payment, and the app asks the Play app on your phone whether you own it. That check runs between two apps on your phone and sends nothing to me. All I receive is the limited order detail Google shares with every developer, for tax, refunds and records.

So my cost per user is close to zero, and charging you every month for a server that does not exist would be strange. The one-time price pays for the work of building it. It is my time, not infrastructure.

The privacy reason

There is a second reason, and for a cycle app it matters more.

A subscription business needs to know who you are. It needs an account to bill, a way to reach you when the card fails, and usually a reason to keep you opening the app so you do not cancel. Each of those pulls data toward the company. None of that is sinister. It is what the model requires.

I wanted the opposite pull. No account means there is nothing to tie your cycle to your name. No server means there is nothing for me to see, and nothing for anyone to ask me for. A one-time purchase through Google Play fits that, because the only record is Google’s order, and orders are never linked to anything you log. The business model and the privacy promise are the same decision seen from two sides. If I ever wanted to sell a subscription, the first thing I would need is exactly the thing I promised not to collect.

How it compares, briefly

For context, and only for context: the big subscription cycle apps charge around 40 US dollars a year. They are large products with teams and servers behind them, and they charge what a product like that costs to run. I am not saying they are wrong to. I am saying Ferrabelle is a different kind of thing, one person’s app with no server, and its price reflects that.

What I will not promise

I will not promise the price never changes. It already did once, from 4.99 to 9.99, in October 2026, and it may move again as the app grows. What I will promise is the shape: if you buy Pro, you own it, and I will not come back next year asking you to renew. That is what a one-time product means on Google Play.

I am aware a one-time price is not the standard move for a cycle app in 2026. I made the same choice about the app itself, building it for one person first and keeping every byte on her phone. The pricing follows from that. It would have been odd to build an app with nothing to see and then ask for a monthly fee to keep not seeing it.

Who this is for

If you have been looking for a period tracker app without subscription, this is one, and the free part is a complete tracker on its own. Try the free app first. If the training forecast, the score history and the partner notes earn their place in your week, Pro is there, once.

Ferrabelle is in a closed test on Google Play right now. If you want to try it, you can join at ferrabelle.com/testers.

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