# Core vs Interval Flow

The clearest difference is review sentiment: Core at 100% against Interval Flow's 48%. Core also leads on monetization model (freemium vs subscription) and rating (5.0 vs 4.7). Interval Flow's advantage is update cadence (fortnightly vs every 33 months) and ratings volume (167 vs 4). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Core sells 3 in-app purchases, starting at $1.99 per month and Interval Flow sells 10 in-app purchases, starting at $4.99 per 3 months. Whichever you choose, the download price is not the number that matters.

Core holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Interval Flow has 167 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 100% of Core's written reviews are positive against 48% of Interval Flow's.

Core ships an update every 33 months, Interval Flow fortnightly. The most recent releases landed on October 30, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | Core | Interval Flow |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/core-interval-and-hiit-timer/id1562215374/reviews)** | [4.7 (167 ratings)](https://appshunter.io/ios/app/interval-flow-wod-timer/id6444124987/reviews) |
| Number of ratings | 4 | **167** |
| Positive reviews | **100.0% of reviews** | 48.1% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 33 months | **Fortnightly** |
| Monetization | **Freemium** | Subscription |
| Size | 9 MB | 20 MB |
| Requires iOS | **15.0** | 18.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yating Lu](https://appshunter.io/developer/1526204219) | [Bence Kaposzta](https://appshunter.io/developer/1650069302) |

## What reviewers say

### Core

[App page](https://appshunter.io/ios/app/core-interval-and-hiit-timer/id1562215374)

This app helps you stay focused during workouts by managing intervals, work times, and rest periods with clear visual and audio cues. Save custom routines for HIIT, Tabata, or boxing, and track your training history to monitor progress.

**Highlights:** Customizable interval timers, Audio cues for work/rest phases, Save and reuse workout routines, Visual countdown and color coding, Workout history and trend tracking, Optional Pro features via in-app purchase

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $1.99 | per month |
| Yearly | $9.99 | per year |
| Lifetime | $14.99 | one-time |


### Interval Flow

[App page](https://appshunter.io/ios/app/interval-flow-wod-timer/id6444124987)

This app revolutionizes fitness routines with deep customization and advanced tracking for various activities like HIIT, Yoga, and CrossFit. It allows users to create, share, and follow personalized workouts with features like color-coded intervals, real-time progress tracking, and voice assistance.

**Highlights:** Color-coded intervals, Customizable circuits, Real-time progress tracking, Voice assist and search, Exercise library, Workout sharing

**Features:** macOS Compatibility

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 3 Month | $4.99 | per 3 months |
| 1 Month | $9.99 | per month |
| 1 Month, 3 day trial | $9.99 | per month |
| Annual | $14.99 | per year |
| 1 Year discounted | $25.95 | per year |
| 1 Year, 3 day trial | $39.99 | per year |
| 1 Year | $39.99 | per year |
| 1 Year Intro month | $39.99 | per year |
| Free Lifetime subscription | Free | one-time |
| Lifetime | $24.99 | one-time |

**What reviewers like**

- 👍 Nicely designed with good features
- 👍 Unique and brilliantly for keeping fit
- 👍 Simplicity gets it done

**What reviewers complain about**

- 🐛 App crashes on launch
- 🐛 App doesn't remember interval settings
- 🐛 App rearranges workout order
- 🐛 Cannot see questionnaire properly
- 🐛 Robot voice with no visual instructions

**Reported bugs**

- Programs deleted after update
- App crashes when adding a program
- Show/Hide Instructions adds time to interval
- App defaults to unused workout
- Cannot permanently skip to end of timed activity

**Requested features**

- Increase repetitions to 20
- Streamline adding intervals
- Make it possible to hide unused workouts
- Add music integration or option
- Provide visual instructions for moves


## Frequently asked questions

### Is Core free?

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

### Is Interval Flow free?

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

### Which has better reviews, Core or Interval Flow?

Core is rated higher. Core averages 5.0 out of 5 from 4 ratings, while Interval Flow averages 4.7 from 167 ratings.

### Do Core or Interval Flow have ads?

Neither Core nor Interval Flow shows ads.

### Which is updated more often, Core or Interval Flow?

Core ships an update every 33 months, and Interval Flow fortnightly. Most recently, Core was updated on October 30, 2026 and Interval Flow on October 23, 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.*