Hejje / Best private fitness apps
Which fitness apps actually keep your training to yourself, what the word private is doing in each of their descriptions, and a short test you can run on any app before you trust it with a year of your history.
Who wrote this
We make Hejje, one of the apps listed below. That is a reason to read the rest of this page sceptically, which is why the criteria come before the list and why the test at the bottom works on our app as well as anyone else's. Features change; everything here reflects September 2026 and is worth checking yourself.
Almost every fitness app says something about privacy, and they mean different things by it. Separating them is most of the work, because an app can be excellent at one and indifferent to the rest.
This is the one people mean and the one least often answered. An app where your activities are hidden from other users still holds them in readable form on its own servers. The alternatives are storing nothing remotely at all, end-to-end encryption, or self-hosting.
An email address ties your training to the rest of your online life and is the thing that leaks in a breach. Some apps need no account. Some, including ours, need one that carries no identifier.
This one is underrated as a privacy property rather than a convenience. An app that functions with the radio off is an app that demonstrably did not need to send anything to do the job.
Advertising, analytics, attribution and crash reporting libraries send data to companies that are not the app's developer, regardless of how carefully the app itself behaves. This is the question most privacy pages skip.
Free, open source and Android only. Records activities with no account and no cloud component, which makes it about as unambiguous as this category gets: there is no server to trust. The interface is functional rather than polished, and there is no strength or nutrition side.
Also free, open source and Android only, and also ad-free with no account. Similar shape to OpenTracks with a different interface. If you only track cardio and you run Android, one of these two is the honest starting point and neither of them needs to be argued for.
Self-hosted. You run the server, so the question of what the operator can read has an easy answer: you are the operator. The cost is that you have to be the sort of person who wants to run a server, and it is a web application rather than a phone-first recorder.
Android, free, long-established, and entirely offline with no account. Plain and fast, which is most of what a set logger needs to be. No cardio tracking and no nutrition.
There is a steady supply of small apps in this space, several of them good, whose whole pitch is local storage and no sign-up. They come and go, so rather than name a shortlist that dates badly, apply the test at the bottom of this page: check the store listing's data-safety section and try it in airplane mode on day one.
Worth naming honestly because they are what most people actually use and they are good at the job. They are cloud accounts with readable server-side storage and paid tiers. If privacy is not your first criterion, they are better lifting apps than most of the privacy-first options, and pretending otherwise would make this page less useful.
This is where the category thins out. The open-source GPS trackers do not do strength training. The offline gym loggers do not do routes. Nutrition is usually a third app, and the mainstream nutrition apps are among the most aggressive data collectors in fitness.
Ours, so weigh it accordingly. It covers walking, running, hiking and cycling with GPS, gym training from a catalogue of 750 exercises, and nutrition from more than 13,000 built-in foods, plus water and weight, in one encrypted history. Signing up asks for a first name and nothing else, everything works offline, and there are no advertising or analytics SDKs in either app.
The honest limits: it is not open source, so our encryption claim is one you currently have to take on trust rather than verify. There is no way to import a Strava history yet. There are no segments or leaderboards and there never will be, because ranking everyone up a hill needs a server that can read everyone's routes. It does not connect to a watch or a bike computer. And a small amount is readable on our side, plus a third category, the shape of the data, that encryption does not hide; all of it is listed on our privacy page and in this post.
None of the above should be taken on the word of a page written by a developer in the category. These four checks take about ten minutes and work on any fitness app, including ours.
Free on iPhone and Android. No email needed to begin, and nothing leaves your phone until you say so.
iOS 17 or later · Android 8.0 or later
Hejje