# Selfloops Spark vs Circular45

The clearest difference is in-app purchases: Circular45 at none against Selfloops Spark's 1. Circular45 also leads on iOS requirement (15.0 vs 18.0). Selfloops Spark's advantage is update cadence (every 2 weeks vs every 8 months). On price, ads and device support there is nothing between them.

Both are free to download. Selfloops Spark sells 1 in-app purchase, starting at $69.99 per year. Circular45 asks for nothing beyond the download.

Selfloops Spark ships an update every 2 weeks, Circular45 every 8 months. The most recent releases landed on October 8, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Selfloops Spark | Circular45 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.7 (13 ratings)](https://appshunter.io/ios/app/selfloops-spark/id1282997660/reviews)** | — |
| Number of ratings | **13** | — |
| Positive reviews | 25.9% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 8 months |
| Monetization | Free with in-app purchases | — |
| Size | 44 MB | 26 MB |
| Requires iOS | 18.0 | **15.0** |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [SelfLoops](https://appshunter.io/developer/911739721) | [Fernando Quintana](https://appshunter.io/developer/1758379392) |

## What reviewers say

### Selfloops Spark

[App page](https://appshunter.io/ios/app/selfloops-spark/id1282997660)

This app helps athletes and fitness enthusiasts track, analyze, and optimize their workouts. It offers personalized training plans, goal setting, and performance insights. Connect with coaches and other users for motivation and feedback.

**Highlights:** Workout tracking and analysis, Fitness challenges and goal setting, Personalized training plans, Heart rate monitoring, RPE logging, Data syncing with Apple Health, Advanced performance analytics

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Athlete Premium | $69.99 | per year |


### Circular45

[App page](https://appshunter.io/ios/app/circular45/id6743935192)

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

**In-app purchases:** none


## Frequently asked questions

### Is Selfloops Spark free?

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

### Is Circular45 free?

Circular45 is free to download, with no in-app purchases.

### Do Selfloops Spark or Circular45 have ads?

Neither Selfloops Spark nor Circular45 shows ads.

### Which is updated more often, Selfloops Spark or Circular45?

Selfloops Spark ships an update every 2 weeks, and Circular45 every 8 months. Most recently, Selfloops Spark was updated on October 8, 2026 and Circular45 on October 4, 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.*