# NDCalc2 vs LensTrails

The clearest difference is price: LensTrails at Free against NDCalc2's $0.99. LensTrails also leads on update cadence (every 3 days vs every 10 months). NDCalc2's advantage is in-app purchases (none vs 2) and iOS requirement (7.0 vs 17.0). On ads and device support there is nothing between them.

LensTrails is free to download; NDCalc2 costs $0.99 up front. LensTrails sells 2 in-app purchases, starting at $3.99 per month. NDCalc2 asks for nothing beyond the download.

NDCalc2 ships an update every 10 months, LensTrails every 3 days. The most recent releases landed on September 21, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | NDCalc2 | LensTrails |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[1.5 (2 ratings)](https://appshunter.io/ios/app/ndcalc2/id822835884/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 months | **Every 3 days** |
| Monetization | Paid | — |
| Size | 20 MB | 87 MB |
| Requires iOS | **7.0** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Boris Nienke](https://appshunter.io/developer/300699195) | [Jerome Bei](https://appshunter.io/developer/1896766887) |

## What reviewers say

### NDCalc2

[App page](https://appshunter.io/ios/app/ndcalc2/id822835884)

Calculate correct exposure times when using ND filters for long exposures. Easily manage your filter collection, add custom filters, and switch between single and multi-select modes for stacking.

**Highlights:** Calculate exposure time with ND filters, Supports iPhone 5/s/c screens, Multi-Select Mode for filter stacking, Add custom ND filters, Delete and reorder filters, Countdown timer for long exposures

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

**In-app purchases:** none


### LensTrails

[App page](https://appshunter.io/ios/app/lenstrails/id6788136488)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $3.99 | per month |
| Pro Yearly | $44.99 | per year |


## Frequently asked questions

### Is NDCalc2 free?

NDCalc2 costs $0.99, with no in-app purchases.

### Is LensTrails free?

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

### Do NDCalc2 or LensTrails have ads?

Neither NDCalc2 nor LensTrails shows ads.

### Which is updated more often, NDCalc2 or LensTrails?

NDCalc2 ships an update every 10 months, and LensTrails every 3 days. Most recently, NDCalc2 was updated on September 21, 2026 and LensTrails on September 25, 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.*