# Alfredo Backer vs Circle & Sphere

The clearest difference is in-app purchases: Alfredo Backer at none against Circle & Sphere's 8. Circle & Sphere's advantage is update cadence (every 3 weeks vs every 8 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Circle & Sphere sells 8 one-off in-app purchases. Alfredo Backer asks for nothing beyond the download.

Alfredo Backer ships an update every 8 months, Circle & Sphere every 3 weeks. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Alfredo Backer | Circle & Sphere |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.0 (4 ratings)](https://appshunter.io/ios/app/circle-and-sphere/id1564077078/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 3 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 55 MB | 180 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Externato Alfredo Backer Ltda](https://appshunter.io/developer/1535072495) | [Glindemann, Sennoun, Langer GbR](https://appshunter.io/developer/1024972809) |

## What reviewers say

### Alfredo Backer

[App page](https://appshunter.io/ios/app/alfredo-backer/id1212354980)

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

**In-app purchases:** none


### Circle & Sphere

[App page](https://appshunter.io/ios/app/circle-and-sphere/id1564077078)

Instantly solve geometry problems for homework and exams. Calculate circle and sphere properties with step-by-step solutions. Access learning videos and manage your calculations.

**Highlights:** Circle calculations (radius, diameter, circumference, area), Sphere calculations (surface area, volume), Circular sector calculations, Step-by-step solutions, Learning videos, Solution management

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| +30 User Tokens | $0.29 | one-time |
| +1 Convenience Token / 6h, max. +2 | $0.59 | one-time |
| +2 Convenience Tokens / 6h, max. +4 | $0.99 | one-time |
| +150 User Tokens | $0.99 | one-time |
| +300 User Tokens | $1.49 | one-time |
| +4 Convenience Tokens / 6h, max. +8 | $1.59 | one-time |
| Remove Ads | $2.99 | one-time |
| Lifetime Access | $2.99 | one-time |


## Frequently asked questions

### Is Alfredo Backer free?

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

### Is Circle & Sphere free?

Circle & Sphere is free to download, with in-app purchases available.

### Do Alfredo Backer or Circle & Sphere have ads?

Neither Alfredo Backer nor Circle & Sphere shows ads.

### Which is updated more often, Alfredo Backer or Circle & Sphere?

Alfredo Backer ships an update every 8 months, and Circle & Sphere every 3 weeks. Most recently, Alfredo Backer was updated on November 2, 2026 and Circle & Sphere on November 3, 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.*