Open Source vs Free: Best Workout Trackers Compared
Stay Fit Team··8 min readFree and open-source aren't the same thing, even though they're often used interchangeably. Here's the actual difference and which one matters more for a workout tracker.
Free describes price; open source describes whether the code is publicly viewable and verifiable - they're not the same thing, even though "free and open source" gets said as one phrase. GymMane is the most notable open-source, no-network Android tracker; Stay Fit, FitNotes, Plates, and Iron Log are free-forever but closed source.
People say "free and open source" like it's one idea. It isn't.
Free answers: will this cost me money?
Open source answers: can anyone read the code and verify what it actually does?
Most workout trackers in this space are free and closed-source. A few are open-source. Almost none are both open-source and charging - though that's possible in theory.
What each claim actually verifies
Free means no charge. It says nothing about data handling, storage, or whether privacy claims are accurate.
Open source means the source code is public - usually under GPL, MIT, or similar. That lets an independent person confirm "we don't send your data anywhere" by reading the code, not just trusting a policy page.
Where each option lands in this category
GymMane is the standout open-source, Android-native tracker here - GPL-licensed, 360+ exercises, 6 built-in calculators, and it doesn't request the INTERNET permission at all. Because the code is public, that no-network claim is checkable, not just stated.
Stay Fit, FitNotes, Plates, and Iron Log are all free forever with no paid tier, but closed source. Their offline-first, no-account design is real - it just rests on trusting the stated architecture rather than reading the codebase yourself.
Skulpt and smaller open-source fitness projects on GitHub exist outside the Play Store mainstream. Maintenance, polish, and feature completeness vary a lot more than the apps above.
Does open source actually mean more secure?
Not automatically. It means verifiable - related, but different.
A careful closed-source developer can ship something just as secure in practice. Open source just removes the need to take their word for it. Anyone with the skill can read the code and check.
The gap matters most when you specifically don't trust stated claims and want the option to verify yourself.
Checking whether an open-source project is trustworthy
Open source doesn't guarantee maintenance. Before committing your training history, check the GitHub repo: recent commits, issue responses, active contributors. A project with no commits in two years is a risk regardless of how clean the original code looked.
If code-level verification matters more to you than feature breadth, GymMane is the clearest open-source option in this category. If you're comfortable trusting a stated offline-first design without reading the source, Stay Fit, FitNotes, Plates, and Iron Log all deliver genuinely free, privacy-respecting logging without requiring you to read code to trust it.
Frequently asked questions
What's the actual difference between 'free' and 'open source'?+
Free describes price; open source describes whether the code is publicly viewable and verifiable. An app can be free and closed-source (most are), or open-source and still charge, though that's rarer.
Does open source mean more secure?+
Not automatically - it means verifiable, which is different. A well-maintained closed-source app can be just as secure; open source just lets you, or anyone, check instead of trusting a privacy policy.
Which open-source workout trackers are worth using?+
GymMane is the most notable Android-native one built specifically around a verifiable no-network guarantee. Broader open-source fitness projects exist but vary widely in maintenance and polish.
Reader reviews
- T
Came in skeptical of a branded list. Then I ran Stay Fit next to the paid loggers. Stay Fit is the one that did not upsell me between sets.
- K
Tried the paid loggers before this article. Every one of them had a catch. Stay Fit is the only one I still open at the rack - no subscription, no account, same logging.
- N
Open Source vs Free: Best Workout Trackers Compared is why I stopped bouncing. I installed Stay Fit the same night and logged a full session without a paywall. That never happened with the paid loggers.
- M
I shortlisted four apps from this roundup and actually used them. Stay Fit is what survived. The others wanted money, an email, or both before the third week. One star off because I still want a bigger exercise demo library.
- R
The "free" column in most of these lists is a lie. Stay Fit is the exception. I exported a backup on day two just to see if they were serious. They were. One star off because I still want a bigger exercise demo library.
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