# S2 vs Stacked

The clearest difference is rating: Stacked at 4.6 against S2's 4.1. Stacked also leads on in-app purchases (none vs 2) and review sentiment (66% vs 41%). S2's advantage is update cadence (fortnightly vs every 6 weeks). On price, ads, monetization model and device support there is nothing between them.

Both are free to download. S2 sells 2 in-app purchases, starting at $22.99 per year. Stacked asks for nothing beyond the download.

Stacked holds the better App Store score, 4.6 against 4.1. That said, the two scores are not equally well evidenced: Stacked has 1.6K ratings behind it against 126, so its average is the more settled of the two. Written reviews point the same way: 41% of S2's written reviews are positive against 66% of Stacked's.

S2 ships an update fortnightly, Stacked every 6 weeks. The most recent releases landed on October 12, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | S2 | Stacked |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.1 (126 ratings)](https://appshunter.io/ios/app/s2-strength-log/id1007310227/reviews) | **[4.6 (1.6K ratings)](https://appshunter.io/ios/app/stacked-workout-tracker-for/id1116989938/reviews)** |
| Number of ratings | 126 | **1.6K** |
| Positive reviews | 41.3% of reviews | **65.8% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 6 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 9 MB | 110 MB |
| Requires iOS | 16.0 | **11.0** |
| Devices | iPhone | **iPhone, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [Formbound AB](https://appshunter.io/developer/531002945) | [M4L, Inc.](https://appshunter.io/developer/734641270) |

## What reviewers say

### S2

[App page](https://appshunter.io/ios/app/s2-strength-log/id1007310227)

This app helps you track and visualize your gym workout progress, encouraging progressive overload for weight loss or muscle gain. It offers a fast, intuitive interface with over 1000 exercises and a unique muscle fatigue heat map. No account is needed, and it integrates with HealthKit.

**Highlights:** Track and visualize workout progress, Muscle fatigue heat map, Create unlimited workout routines, Encourages progressive overload, 1000+ exercises, Workout history review, HealthKit integration

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| S2 Yearly | $22.99 | per year |
| Strongly Pro | $4.99 | one-time |


### Stacked

[App page](https://appshunter.io/ios/app/stacked-workout-tracker-for/id1116989938)

This application helps users plan and track weightlifting workouts to build muscle and strength. It offers a clean interface designed by weightlifters for weightlifters, with features for routine creation, progress tracking, and automatic plate calculations.

**Highlights:** Plan and track weightlifting workouts, Create simple or complex routines, Track personal records, Automatic plate math, Review past workout data, Cloud data backup

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 👍 Intuitive interface
- 👍 Comprehensive workout tracking
- 👍 Detailed progress monitoring
- 👍 Preloaded workouts from popular programs

**What reviewers complain about**

- 🐛 Occasional crashes and bugs
- 🐛 Unreliable data saving and syncing
- 🐛 Inability to edit or delete workouts
- 🐛 Inconsistent weight/plate input
- 🐛 Confusing user interface in parts

**Reported bugs**

- Workout data not saving properly
- Inability to log certain weight increments
- Frequent crashes and freezes
- Sync issues causing loss of workout history
- Incorrect default weight display

**Requested features**

- Ability to edit and delete workouts
- More customization options for workouts and routines
- Integration with Apple Health and other fitness apps
- Exercise demonstration videos or GIFs
- Superset and triset functionality


## Frequently asked questions

### Is S2 free?

S2 is free to download, with in-app purchases available.

### Is Stacked free?

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

### Which has better reviews, S2 or Stacked?

Stacked is rated higher. S2 averages 4.1 out of 5 from 126 ratings, while Stacked averages 4.6 from 1.6K ratings.

### Do S2 or Stacked have ads?

Neither S2 nor Stacked shows ads.

### Which is updated more often, S2 or Stacked?

S2 ships an update fortnightly, and Stacked every 6 weeks. Most recently, S2 was updated on October 12, 2026 and Stacked on October 17, 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.*