# LSI Calculator vs Doc Scan：OCR and PDF Scanner

The clearest difference is review sentiment: LSI Calculator at 100% against Doc Scan：OCR and PDF Scanner's 15%. LSI Calculator also leads on rating (4.4 vs 3.5) and in-app purchases (none vs 8). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Doc Scan：OCR and PDF Scanner sells 8 in-app purchases, starting at $4.99 per 7 days. LSI Calculator asks for nothing beyond the download.

LSI Calculator holds the better App Store score, 4.4 against 3.5. Both are backed by a comparable volume of ratings — 5 and 8 respectively. Written reviews point the same way: 100% of LSI Calculator's written reviews are positive against 15% of Doc Scan：OCR and PDF Scanner's.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on June 11, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | LSI Calculator | Doc Scan：OCR and PDF Scanner |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (5 ratings)](https://appshunter.io/ios/app/lsi-calculator/id1233049990/reviews)** | [3.5 (8 ratings)](https://appshunter.io/ios/app/doc-scanocr-and-pdf-scanner/id1542570430/reviews) |
| Number of ratings | 5 | **8** |
| Positive reviews | **100.0% of reviews** | 15.4% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 52 MB | 72 MB |
| Requires iOS | **11.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Pure Planet Science & Technology, Inc.](https://appshunter.io/developer/1234693265) | [Hangzhou Jiadi Bozhong](https://appshunter.io/developer/1506720843) |

## What reviewers say

### LSI Calculator

[App page](https://appshunter.io/ios/app/lsi-calculator/id1233049990)

This app provides tools and educational resources to help users manage water systems, focusing on eco-friendly treatments for pools and spas. It aims to make water maintenance accessible to everyone, regardless of their experience level.

**Highlights:** Water science education, Pool and spa water management, Eco-friendly treatment guidance, NSF/ANSI Certified product information, Tools for water system management

**Features:** macOS Compatibility

**In-app purchases:** none


### Doc Scan：OCR and PDF Scanner

[App page](https://appshunter.io/ios/app/doc-scanocr-and-pdf-scanner/id1542570430)

This app acts as a smart scanning assistant, converting documents and images into editable text and PDFs. It offers features like OCR text recognition, ID card scanning, and photo translation, simplifying manual input and typesetting for students and office workers.

**Highlights:** Document scanning, OCR text recognition, ID card scanning, Photo translation, Image to Word conversion, PDF conversion

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 扫描仪全能王-周会员 | $4.99 | per 7 days |
| monthly member | $6.99 | per month |
| weekly member | $9.99 | per 7 days |
| one-year member | $29.99 | per year |
| Quarterly member | $39.99 | per 3 months |
| 一个月高级版 | $2.99 | one-time |
| 三个月vip | $5.99 | one-time |
| 永久会员 | $39.99 | one-time |


## Frequently asked questions

### Is LSI Calculator free?

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

### Is Doc Scan：OCR and PDF Scanner free?

Doc Scan：OCR and PDF Scanner is free to download, with in-app purchases available.

### Which has better reviews, LSI Calculator or Doc Scan：OCR and PDF Scanner?

LSI Calculator is rated higher. LSI Calculator averages 4.4 out of 5 from 5 ratings, while Doc Scan：OCR and PDF Scanner averages 3.5 from 8 ratings.

### Do LSI Calculator or Doc Scan：OCR and PDF Scanner have ads?

Neither LSI Calculator nor Doc Scan：OCR and PDF Scanner shows ads.

### Which is updated more often, LSI Calculator or Doc Scan：OCR and PDF Scanner?

LSI Calculator ships an update every 2 months, and Doc Scan：OCR and PDF Scanner every 2 months. Most recently, LSI Calculator was updated on June 11, 2026 and Doc Scan：OCR and PDF Scanner on September 21, 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.*