# Plank Challenge vs OpenBox App

The clearest difference is in-app purchases: OpenBox App at none against Plank Challenge's 1. OpenBox App also leads on ads (none vs shown). Plank Challenge's advantage is update cadence (every 3 weeks vs every 3 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Plank Challenge sells 1 one-off in-app purchase. OpenBox App asks for nothing beyond the download.

Plank Challenge ships an update every 3 weeks, OpenBox App every 3 months. The most recent releases landed on October 16, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Plank Challenge | OpenBox App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (470 ratings)](https://appshunter.io/ios/app/plank-challenge-core-workout/id1083360252/reviews)** | — |
| Number of ratings | **470** | — |
| Positive reviews | 67.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | Free with in-app purchases | — |
| Size | 17 MB | 67 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Bo Kalvslund](https://appshunter.io/developer/572272193) | [Tecnologia y Desarrollo Informatico S.R.L.](https://appshunter.io/developer/1621745764) |

## What reviewers say

### Plank Challenge

[App page](https://appshunter.io/ios/app/plank-challenge-core-workout/id1083360252)

This app guides you through a 5-week program to build up to a 4-minute plank. It requires no equipment and can be done in just 4 minutes daily, with rest days incorporated for recovery. It also includes a bonus push-up progression.

**Highlights:** 5-week structured plank program, Progressive push-up training, Daily workout instructions, Progress tracking, Apple Music integration, Distraction-free interface

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plank Challenge Pro | $0.99 | one-time |

**What reviewers like**

- 👍 Simple and effective
- 💪 Great for plank challenges
- 🎯 Helps build stamina
- ✅ Good for beginners
- ✨ Straightforward design

**What reviewers complain about**

- 🔇 Music pauses during sets
- 🎵 Lack of in-app music/motivation
- ❓ No clear guidance on plank types
- 🎛️ No timer customization
- 👎 Push-up part lacks challenge

**Reported bugs**

- App crashes after iOS 13 update
- No times displayed after iOS 13 update
- Audio mutes automatically between active and rest
- App not running after iOS 13 update

**Requested features**

- Allow self-designed workouts
- Integrate reminders
- Add in-app music or motivational sounds
- Provide explanation on different plank types
- Include countdowns and motivational cues


### OpenBox App

[App page](https://appshunter.io/ios/app/openbox-app/id6575386218)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Plank Challenge free?

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

### Is OpenBox App free?

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

### Do Plank Challenge or OpenBox App have ads?

Plank Challenge shows ads; OpenBox App does not.

### Which is updated more often, Plank Challenge or OpenBox App?

Plank Challenge ships an update every 3 weeks, and OpenBox App every 3 months. Most recently, Plank Challenge was updated on October 16, 2026 and OpenBox App on September 20, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*