Libra runs on Android and iPhone, with cloud sync, sharing, and a free tier. Its monthly Pro plan costs less; Trendline's annual plan costs less at current U.S. prices. Trendline is iPhone-only, reads from Apple Health with no extra account or cloud, keeps every reading, and states its uncertainty.
Trendline is an iPhone app that reads Apple Health. If you use Android, Trendline isn't an option, and Libra is a well-established choice there. This page is for iPhone owners. Trendline is not affiliated with Libra or its developer.
First, the honest part
Libra Weight Manager, by Daniel Cachapa, describes its purpose as digging "through the daily measurement swings to put focus on the hidden trends that actually matter" (libra-app.eu). On Google Play it shows more than a million downloads and about 20,000 reviews, and both its Android and iPhone versions were last updated in September 2025 (Google Play and App Store listings, checked October 2026). It tracks body fat and muscle mass as well as weight, connects to Withings scales and, on iPhone, to Apple Health, keeps your data in its own cloud with sync across devices, and lets friends see each other's charts.
Where the two apps genuinely differ
| Libra | Trendline | |
|---|---|---|
| Devices | Android and iPhone | iPhone only |
| How weights get in | Manual entry, Withings scales, and Apple Health on iPhone | Manual entry, plus weight, body fat %, and lean body mass from any app that writes them to Apple Health |
| Trend | A trend through the daily swings; the method is not published | Statistical trend with explicit uncertainty; declines to conclude when evidence is sparse |
| Readings per day | Entries "as often as you like"; how same-day readings combine is not published | Every reading kept, with its time, source, and unit |
| Body composition | Body fat, muscle mass, and other body metrics | Calculated fat and lean mass from paired readings, plus manual entry for values Apple Health has no type for |
| Goals | Goals with planning estimates | Lose Weight, Build Lean, and Maintain as distinct phases, with a goal forecast |
| Storage and sharing | Libra Cloud with sync and backups; share charts with friends | On the device; Apple Health is the only "account", Trendline runs no iCloud sync service, and nothing is shared without an explicit action |
| Price | Free with ads; on iPhone, Pro is $1.99/month or $17.99/year (App Store listing, October 2026) | $0.99/week · $3.99/month · $10.99/year · $34.99 lifetime |
Libra offers a free tier, a lower monthly price, Android support, cloud sync, and a social side. Trendline's annual plan costs less than Libra Pro's at the U.S. prices above. What Trendline offers on iPhone is a trend that states its uncertainty, every reading kept with its provenance, losing, building, and maintaining treated as different jobs, and no account or cloud beyond Apple Health. The full math is public on the methodology page.
Who should pick which
- Pick Libra if you use Android or switch between platforms, want cloud sync across devices, want to share charts with friends, or want the free tier.
- Pick Trendline if you're on iPhone, want your weigh-ins read straight from Apple Health with no extra account or cloud, keep several readings a day, or want the trend to admit uncertainty.
Try the idea
Paste a few weeks of weigh-ins into the free weight trend calculator to see a slower signal drawn against every reading. It runs in any browser, Android included.
Questions people ask
Is there a Libra app for iPhone?
Yes. Libra runs on Android and iPhone, and on iPhone it connects to Apple Health. Trendline is iPhone only.
How much does Libra cost?
Libra is free with ads. On iPhone, Pro is $1.99/month or $17.99/year (App Store listing, October 2026).
Does Libra track body fat?
Yes. Libra tracks body fat and muscle mass as well as weight (libra-app.eu and its store listings).
Where does Libra store my data?
In Libra Cloud, with sync and backups, and you can share charts with friends. Trendline keeps data on the device and shares nothing without an explicit action.
Should I pick Libra or Trendline?
Pick Libra if you use Android or switch between platforms, want cloud sync across devices, want to share charts with friends, or want the free tier. Pick Trendline if you're on iPhone, want your weigh-ins read straight from Apple Health with no extra account or cloud, keep several readings a day, or want the trend to admit uncertainty.
Sources
- Libra website (purpose, entry frequency, body metrics, friends)
- Libra on Google Play (version 4.9.17: downloads, ratings, Withings, Libra Cloud)
- Libra Weight Manager on the App Store (version 4.9.17: Apple Health, pricing)
Trendline is not affiliated with or endorsed by Libra or Daniel Cachapa. Facts above were verified against the linked pages on October 3, 2026; app stores change, so check the listings for current pricing.