# Stretch Affect vs PD+

The clearest difference is in-app purchases: Stretch Affect at none against PD+'s 1. Stretch Affect also leads on iOS requirement (11.0 vs 17.6). PD+'s advantage is update cadence (every 2 months vs every 5 months). On price, ads and device support there is nothing between them.

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

Stretch Affect ships an update every 5 months, PD+ every 2 months. The most recent releases landed on October 29, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | Stretch Affect | PD+ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (555 ratings)](https://appshunter.io/ios/app/pd-plus-easy-pupillary-distance/id1560353383/reviews)** |
| Number of ratings | — | **555** |
| Positive reviews | — | 54.2% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | — | Free with in-app purchases |
| Size | 50 MB | 76 MB |
| Requires iOS | **11.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Stretch Affect LLC](https://appshunter.io/developer/1504743026) | [Zernike LLC](https://appshunter.io/developer/1636196510) |

## What reviewers say

### Stretch Affect

[App page](https://appshunter.io/ios/app/stretch-affect/id1504743027)

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

**In-app purchases:** none


### 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?


## Frequently asked questions

### Is Stretch Affect free?

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

### Is PD+ free?

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

### Do Stretch Affect or PD+ have ads?

Neither Stretch Affect nor PD+ shows ads.

### Which is updated more often, Stretch Affect or PD+?

Stretch Affect ships an update every 5 months, and PD+ every 2 months. Most recently, Stretch Affect was updated on October 29, 2026 and PD+ on October 27, 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.*