# Constant Scale vs Biostacks

The clearest difference is in-app purchases: Constant Scale at none against Biostacks's 2. Constant Scale also leads on iOS requirement (11.0 vs 15.1). Biostacks's advantage is update cadence (every 10 days vs every 4 weeks). On price, ads and device support there is nothing between them.

Both are free to download. Biostacks sells 2 in-app purchases, starting at $3.99 per month. Constant Scale asks for nothing beyond the download.

Constant Scale ships an update every 4 weeks, Biostacks every 10 days. The most recent releases landed on September 10, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | Constant Scale | Biostacks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/biostacks-supplement-tracker/id6763328808/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 weeks | **Every 10 days** |
| Monetization | — | Freemium |
| Size | 150 MB | 63 MB |
| Requires iOS | **11.0** | 15.1 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Yiwu Chaolan Import & Export Co., Ltd.](https://appshunter.io/developer/1788815884) | [Hmujo LLC](https://appshunter.io/developer/1895266544) |

## What reviewers say

### Constant Scale

[App page](https://appshunter.io/ios/app/constant-scale/id6740186656)

**Features:** macOS Compatibility

**In-app purchases:** none


### Biostacks

[App page](https://appshunter.io/ios/app/biostacks-supplement-tracker/id6763328808)

Easily manage your supplement intake with barcode scanning, AI assistance, and detailed insights. Track routines, monitor nutrient coverage, and analyze your stack's effectiveness and cost. Prioritizes user privacy with offline functionality and optional iCloud sync.

**Highlights:** Barcode scanning for supplement library, AI-powered supplement routine analysis, Customizable daily and cycle schedules, StackScore for routine quality, Potential interaction warnings, RDA coverage and nutrient overlap analysis, Mood, energy, and sleep trend tracking

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Biostacks Pro - Monthly | $3.99 | per month |
| Biostacks Pro - Annual | $24.99 | per year |


## Frequently asked questions

### Is Constant Scale free?

Constant Scale is free to download, with no in-app purchases.

### Is Biostacks free?

Biostacks is free to download, with in-app purchases available.

### Do Constant Scale or Biostacks have ads?

Neither Constant Scale nor Biostacks shows ads.

### Which is updated more often, Constant Scale or Biostacks?

Constant Scale ships an update every 4 weeks, and Biostacks every 10 days. Most recently, Constant Scale was updated on September 10, 2026 and Biostacks on September 18, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*