# PD+ vs SabStab

The clearest difference is review sentiment: SabStab at 100% against PD+'s 54%. SabStab also leads on in-app purchases (none vs 1) and update cadence (every 6 days vs every 2 months). PD+'s advantage is ratings volume (557 vs 2). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. PD+ sells 1 one-off in-app purchase. SabStab asks for nothing beyond the download.

SabStab holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: PD+ has 557 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 54% of PD+'s written reviews are positive against 100% of SabStab's.

PD+ ships an update every 2 months, SabStab every 6 days. The most recent releases landed on November 3, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | PD+ | SabStab |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (557 ratings)](https://appshunter.io/ios/app/pd-plus-easy-pupillary-distance/id1560353383/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/sabstab/id6798914749/reviews)** |
| Number of ratings | **557** | 2 |
| Positive reviews | 54.2% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 6 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 76 MB | 115 MB |
| Requires iOS | 17.6 | **16.4** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Zernike LLC](https://appshunter.io/developer/1636196510) | [Emmanuel Alvarado](https://appshunter.io/developer/6798914751) |

## What reviewers say

### PD+

[App page](https://appshunter.io/ios/app/pd-plus-easy-pupillary-distance/id1560353383)

This app measures pupillary distance (PD) and fitting heights using your device's camera. It offers various optical calculators for lens adjustments and acuity estimations. Accurate measurements are crucial for optimal lens centering and multifocal lens positioning.

**Highlights:** Pupillary distance measurement, Fitting height measurement, Binocular and monocular PD, Rx transposition calculator, Vertex adjustment calculator, Crossed cylinders calculator, Minimum blank size calculator

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Subscription | $7.99 | one-time |

**What reviewers like**

- 👍 Easy and quick measurement
- 💡 Clever and innovative app
- ⭐ Highly accurate measurements
- 👍 Friendly and easy to use
- 🗣️ Voice instructions included

**What reviewers complain about**

- 📉 Unstable measurements
- ❓ Measurement inconsistency
- ❌ Inaccurate PD readings
- 🤔 Measurements not trustworthy
- 📏 PD off by several mm

**Reported bugs**

- Face size unstable
- Camera distance sensitive
- App keeps crashing
- PD feature doesn't work on iPad
- Page stays black on iPad

**Requested features**

- Can this app measure the PD for progressive lenses for right and left eyes?


### SabStab

[App page](https://appshunter.io/ios/app/sabstab/id6798914749)

This app applies biomechanics to strength training with a 3D muscle model and animated charts. It offers personalized routines based on your goals, equipment, and logs, with detailed exercise guides and progress tracking.

**Highlights:** 3D muscle figure visualization, Personalized workout routines, Animated progress charts, Detailed exercise guides, Offline workout logging, Customizable appearance settings

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

**In-app purchases:** none


## Frequently asked questions

### Is PD+ free?

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

### Is SabStab free?

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

### Which has better reviews, PD+ or SabStab?

SabStab is rated higher. PD+ averages 4.7 out of 5 from 557 ratings, while SabStab averages 5.0 from 2 ratings.

### Do PD+ or SabStab have ads?

Neither PD+ nor SabStab shows ads.

### Which is updated more often, PD+ or SabStab?

PD+ ships an update every 2 months, and SabStab every 6 days. Most recently, PD+ was updated on November 3, 2026 and SabStab on November 6, 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.*