# SparkFast vs Waterfaster

The clearest difference is device support: SparkFast at 4 against Waterfaster's 1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. SparkFast sells 6 in-app purchases, starting at $6.99 per month and Waterfaster sells 3 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.

SparkFast ships an update every 6 days, Waterfaster every 11 days. The most recent releases landed on October 4, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | SparkFast | Waterfaster |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 6 days** | Every 11 days |
| Size | 94 MB | 59 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [SparkFast Technologies LLC](https://appshunter.io/developer/1852736867) | [AMIT Solutions](https://appshunter.io/developer/1892726088) |

## What reviewers say

### SparkFast

[App page](https://appshunter.io/ios/app/sparkfast/id6755233574)

**Features:** Apple Watch app

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SparkFast Monthly | $6.99 | per month |
| SparkFast Annual | $48.00 | per year |
| SparkFast Annual | $51.00 | per year |
| SparkFast Annual | $54.00 | per year |
| SparkFast Annual | $57.00 | per year |
| SparkFast Yearly | $64.99 | per year |


### Waterfaster

[App page](https://appshunter.io/ios/app/waterfaster-fasting-tracker/id6762065095)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Waterfaster+ | $3.99 | per 7 days |
| Waterfaster+ | $44.99 | per year |
| Lifetime | $89.99 | one-time |


## Frequently asked questions

### Is SparkFast free?

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

### Is Waterfaster free?

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

### Do SparkFast or Waterfaster have ads?

Neither SparkFast nor Waterfaster shows ads.

### Which is updated more often, SparkFast or Waterfaster?

SparkFast ships an update every 6 days, and Waterfaster every 11 days. Most recently, SparkFast was updated on October 4, 2026 and Waterfaster on October 5, 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.*