# Seconds Interval Timer vs Catalyst Fort Mill Online

The clearest difference is in-app purchases: Catalyst Fort Mill Online at none against Seconds Interval Timer's 1. Catalyst Fort Mill Online also leads on iOS requirement (15.5 vs 18.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Seconds Interval Timer sells 1 one-off in-app purchase. Catalyst Fort Mill Online asks for nothing beyond the download.

Seconds Interval Timer ships an update monthly, Catalyst Fort Mill Online every 3 weeks. The most recent releases landed on October 28, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | Seconds Interval Timer | Catalyst Fort Mill Online |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (24K ratings)](https://appshunter.io/ios/app/seconds-interval-timer/id475816966/reviews)** | — |
| Number of ratings | **24K** | — |
| Positive reviews | 74.5% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | Free with in-app purchases | — |
| Size | 99 MB | 173 MB |
| Requires iOS | 18.0 | **15.5** |
| Devices | iPhone, iPad, Apple Watch | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Runloop Ltd](https://appshunter.io/developer/325563420) | [Catalyst Personal Training LLC](https://appshunter.io/developer/1755577872) |

## What reviewers say

### Seconds Interval Timer

[App page](https://appshunter.io/ios/app/seconds-interval-timer/id475816966)

This app provides a versatile interval timer for various workout types like Tabata, HIIT, and circuit training. It features a clear, full-screen display, customizable alerts, and background operation. Users can also utilize a stopwatch and countdown timer, with integration for Apple Health.

**Highlights:** Full-screen colored display, Templates for HIIT, Tabata, Circuit Training, Voice and audio alerts, Music assignment per interval, Background operation, Apple Health integration, Stopwatch and countdown timer

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Advanced Version | $7.99 | one-time |

**What reviewers like**

- 🚀 Great workout app
- 👍 Customizable and user-friendly
- 🔒 Reliable and stable
- 💡 Versatile for various workouts
- 👍 Easy to create and edit timers

**What reviewers complain about**

- 🐛 Occasional audio issues
- 🔍 Limited Apple Watch integration
- 💰 Paid version required for full functionality
- 🕰️ Time-consuming to set up complex workouts

**Reported bugs**

- Timer sometimes stops working unexpectedly
- Issues with restoring purchases on new devices

**Requested features**

- Ability to change beep/alert volume independently
- Option to delay transition between intervals
- Sync workouts across devices
- More preset workout templates
- Heart rate monitoring integration


### Catalyst Fort Mill Online

[App page](https://appshunter.io/ios/app/catalyst-fort-mill-online/id6793143232)

**Features:** Apple Wallet, Apple Watch app

**In-app purchases:** none


## Frequently asked questions

### Is Seconds Interval Timer free?

Seconds Interval Timer is free to download, with in-app purchases available.

### Is Catalyst Fort Mill Online free?

Catalyst Fort Mill Online is free to download, with no in-app purchases.

### Do Seconds Interval Timer or Catalyst Fort Mill Online have ads?

Neither Seconds Interval Timer nor Catalyst Fort Mill Online shows ads.

### Which is updated more often, Seconds Interval Timer or Catalyst Fort Mill Online?

Seconds Interval Timer ships an update monthly, and Catalyst Fort Mill Online every 3 weeks. Most recently, Seconds Interval Timer was updated on October 28, 2026 and Catalyst Fort Mill Online on September 29, 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.*