# ProblemSum vs E

The clearest difference is price: E at Free against ProblemSum's $6.99. ProblemSum's advantage is in-app purchases (none vs 7) and update cadence (every 3 weeks vs every 11 months). On rating, ratings volume, ads and device support there is nothing between them.

E is free to download; ProblemSum costs $6.99 up front. E sells 7 one-off in-app purchases. ProblemSum asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for ProblemSum against 5.0 for E. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

ProblemSum ships an update every 3 weeks, E every 11 months. The most recent releases landed on November 3, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | ProblemSum | E |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/problemsum/id1273718042/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/e-cubed-books/id1436898855/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 11 months |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 3 MB | 25 MB |
| Requires iOS | 18.0 | **17.6** |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | +4 | 4+ |
| Developer | [Aeterna Solutions](https://appshunter.io/developer/1273718041) | [James Braunreuther](https://appshunter.io/developer/1436898854) |

## What reviewers say

### ProblemSum

[App page](https://appshunter.io/ios/app/problemsum/id1273718042)

This app provides an unlimited supply of Singapore-style math word problems, with step-by-step solutions. It's designed for children aged 10-13 seeking a challenge and covers a wide range of advanced math topics. The app offers a digital scratchpad for working out problems without a calculator.

**Highlights:** Unlimited word problems, Step-by-step solutions, Digital scratchpad, No calculator required, Singapore math methodology, Covers fractions, ratios, algebra, and more

**Features:** Vision Pro support, iPhone Duo support

**In-app purchases:** none


### E

[App page](https://appshunter.io/ios/app/e-cubed-books/id1436898855)

This app offers an engaging way for children to learn through interactive books. It combines storytelling, proper English, and video content to educate young minds in an entertaining format.

**Highlights:** Interactive books for kids, Educational content, Storytelling, Proper English lessons, Video integration

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

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 E-Cubed Book Coin | $0.99 | one-time |
| 5 E-Cubed Books Coins | $4.99 | one-time |
| 10 E-Cubed Books Coins | $9.99 | one-time |
| 20 E-Cubed Books Coins | $19.99 | one-time |
| 30 E-Cubed Books Coins | $29.99 | one-time |
| 40 E-Cubed Books Coins | $39.99 | one-time |
| 50 E-Cubed Books Coins | $49.99 | one-time |


## Frequently asked questions

### Is ProblemSum free?

ProblemSum costs $6.99, with no in-app purchases.

### Is E free?

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

### Which has better reviews, ProblemSum or E?

ProblemSum and E are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.

### Do ProblemSum or E have ads?

Neither ProblemSum nor E shows ads.

### Which is updated more often, ProblemSum or E?

ProblemSum ships an update every 3 weeks, and E every 11 months. Most recently, ProblemSum was updated on November 3, 2026 and E on November 2, 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.*