# HydraFill vs Calorie Burndown

The clearest difference is in-app purchases: HydraFill at none against Calorie Burndown's 3. HydraFill also leads on iOS requirement (15.0 vs 26.5). Calorie Burndown's advantage is ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. Calorie Burndown sells 3 one-off in-app purchases. HydraFill asks for nothing beyond the download.

HydraFill ships an update every 2 days, Calorie Burndown every 3 days. The most recent releases landed on October 15, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | HydraFill | Calorie Burndown |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hydrafill-hydration-tracker/id6790350987/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 2 days** | Every 3 days |
| Monetization | Free with in-app purchases | — |
| Size | 102 MB | 6 MB |
| Requires iOS | **15.0** | 26.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Parthkumar Saliya](https://appshunter.io/developer/1895160511) | [Kevin McMahon](https://appshunter.io/developer/6783589762) |

## What reviewers say

### HydraFill

[App page](https://appshunter.io/ios/app/hydrafill-hydration-tracker/id6790350987)

Visualize your daily water intake with an animated body silhouette that fills up with each logged drink. Track various beverages, set personalized goals, and receive custom reminders to stay hydrated. Share your progress with engaging visualizations.

**Highlights:** Animated body visualization of hydration, Log 18+ drink types with custom icons, Set personalized daily hydration goals, Customizable drink reminders, Build daily streaks and earn badges, Sync with Apple Health, Track caffeine intake, Home screen widget for quick logging

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

**In-app purchases:** none


### Calorie Burndown

[App page](https://appshunter.io/ios/app/calorie-burndown/id6800660426)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Buy me a coffee | $1.99 | one-time |
| Buy me a few coffees | $4.99 | one-time |
| Buy the whole round | $9.99 | one-time |


## Frequently asked questions

### Is HydraFill free?

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

### Is Calorie Burndown free?

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

### Do HydraFill or Calorie Burndown have ads?

HydraFill shows ads; Calorie Burndown does not.

### Which is updated more often, HydraFill or Calorie Burndown?

HydraFill ships an update every 2 days, and Calorie Burndown every 3 days. Most recently, HydraFill was updated on October 15, 2026 and Calorie Burndown on October 31, 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.*