# LSPIV vs Mini Secchi

The clearest difference is update cadence: Mini Secchi at monthly against LSPIV's every 13 months. LSPIV's advantage is iOS requirement (11.0 vs 13.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

LSPIV ships an update every 13 months, Mini Secchi monthly. The most recent releases landed on June 24, 2026 and August 16, 2026 respectively.

## The numbers

| Metric | LSPIV | Mini Secchi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/lspiv/id981387743/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 13 months | **Monthly** |
| Monetization | Free | — |
| Size | 71 MB | 78 MB |
| Requires iOS | **11.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ryota Tsubaki](https://appshunter.io/developer/981387742) | [DDQ](https://appshunter.io/developer/418328467) |

## What reviewers say

### LSPIV

[App page](https://appshunter.io/ios/app/lspiv/id981387743)

This application enables large-scale particle image velocimetry (LSPIV) using a smartphone. It offers a non-intrusive method for measuring water surface velocity distribution in both field and lab settings. The app provides instant ortho-rectification of captured images without needing ground control points.

**Highlights:** Large-scale particle image velocimetry, Water surface velocity measurement, Non-intrusive velocimetry, Smartphone implementation, Instant ortho-rectification, No GCPs required

**Features:** macOS Compatibility

**In-app purchases:** none


### Mini Secchi

[App page](https://appshunter.io/ios/app/mini-secchi/id1587116779)

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

**In-app purchases:** none


## Frequently asked questions

### Is LSPIV free?

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

### Is Mini Secchi free?

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

### Do LSPIV or Mini Secchi have ads?

Neither LSPIV nor Mini Secchi shows ads.

### Which is updated more often, LSPIV or Mini Secchi?

LSPIV ships an update every 13 months, and Mini Secchi monthly. Most recently, LSPIV was updated on June 24, 2026 and Mini Secchi on August 16, 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.*