# Calculator + vs Smart Purifier

The clearest difference is review sentiment: Calculator + at 85% against Smart Purifier's 0%. Calculator + also leads on rating (4.6 vs 1.0) and ratings volume (10K vs 1). Smart Purifier's advantage is in-app purchases (none vs 12) and ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. Calculator + sells 12 in-app purchases, starting at $4.99 per month. Smart Purifier asks for nothing beyond the download.

Calculator + holds the better App Store score, 4.6 against 1.0. That said, the two scores are not equally well evidenced: Calculator + has 10K ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 85% of Calculator +'s written reviews are positive against 0% of Smart Purifier's.

Calculator + ships an update every 5 days, Smart Purifier fortnightly. The most recent releases landed on October 18, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Calculator + | Smart Purifier |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (10K ratings)](https://appshunter.io/ios/app/calculator-plus/id351815470/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/smart-purifier/id1535735160/reviews) |
| Number of ratings | **10K** | 1 |
| Positive reviews | **84.9% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 5 days** | Fortnightly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 49 MB | 115 MB |
| Requires iOS | 16.4 | **11.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [xNeat.com](https://appshunter.io/developer/327498295) | [VIETTEL GROUP](https://appshunter.io/developer/1529233160) |

## What reviewers say

### Calculator +

[App page](https://appshunter.io/ios/app/calculator-plus/id351815470)

This app offers a free basic and scientific calculator with an intuitive interface. It supports fractions, percentages, and advanced editing. Optional upgrades provide specialized calculators for fractions with units, polynomial and linear equation solving, graphing, and geometric shapes.

**Highlights:** Free basic and scientific calculator, Intuitive interface with equation and result display, Fraction and percent support, Advanced editing capabilities, Polynomial and linear equation solver, Graphing calculator, Unit conversion and geometric calculators

**Features:** Vision Pro support

**In-app purchases (12)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Scientific Calculator | $4.99 | per month |
| Calculator | $39.99 | per year |
| Linear Calculator | $2.99 | one-time |
| Factoring Calculator | $2.99 | one-time |
| Handwriting Calculator | $2.99 | one-time |
| Currency Converter | $2.99 | one-time |
| Themes Pack | $2.99 | one-time |
| Graphing Calculator | $3.99 | one-time |
| Fraction Calculator | $3.99 | one-time |
| Scientific Calculator | $4.99 | one-time |
| Calculator Plus | $4.99 | one-time |
| Calculator | $16.99 | one-time |

**What reviewers like**

- 👍 Great features and easy to use
- 👍 Efficient and quick
- 👍 Versatile, functional calculator
- 👍 Fantastic, easy to use app
- 👍 Awesome calculator app

**What reviewers complain about**

- 🐛 New updated layout is awful
- 🐛 App is now terrible
- 🔒 Paying customer screwed over by update
- 🔒 Now timed trial, no free w/ads version
- 🔒 Not honest

**Reported bugs**

- Fraction calculator has TWO subtraction buttons and NO division button
- Decimals seem to be changed to fraction with no apparent way of changing it back
- Functionality is dropped by forcing you to the main menu every time you open it
- Currency converter broken
- Login screen freezes

**Requested features**

- Add mod function
- Add commas
- Add 1/x function
- Support for Retina Display
- Add number 4 with two lines


### Smart Purifier

[App page](https://appshunter.io/ios/app/smart-purifier/id1535735160)

Monitor and control your Smart Purifier air quality device. View real-time air quality data and adjust settings remotely. Ensure a healthy living environment with this connected appliance management tool.

**Highlights:** Remote device control, Real-time air quality monitoring, Device settings adjustment, Air purification management, Connected appliance integration

**In-app purchases:** none


## Frequently asked questions

### Is Calculator + free?

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

### Is Smart Purifier free?

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

### Which has better reviews, Calculator + or Smart Purifier?

Calculator + is rated higher. Calculator + averages 4.6 out of 5 from 10K ratings, while Smart Purifier averages 1.0 from 1 ratings.

### Do Calculator + or Smart Purifier have ads?

Calculator + shows ads; Smart Purifier does not.

### Which is updated more often, Calculator + or Smart Purifier?

Calculator + ships an update every 5 days, and Smart Purifier fortnightly. Most recently, Calculator + was updated on October 18, 2026 and Smart Purifier on October 1, 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.*