# Howtosmile vs STEM FLEX

The clearest difference is update cadence: STEM FLEX at every 5 days against Howtosmile's every 21 months. Howtosmile's advantage is iOS requirement (7.0 vs 14.0). 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.

Howtosmile ships an update every 21 months, STEM FLEX every 5 days. The most recent releases landed on October 23, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Howtosmile | STEM FLEX |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/howtosmile/id462994547/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 5 days** |
| Monetization | Free | — |
| Size | 1 MB | 30 MB |
| Requires iOS | **7.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [The Lawrence Hall of Science](https://appshunter.io/developer/462994550) | [FableVision, INC](https://appshunter.io/developer/330019981) |

## What reviewers say

### Howtosmile

[App page](https://appshunter.io/ios/app/howtosmile/id462994547)

Discover and perform fun, hands-on STEM activities for all ages. Explore a vast collection of experiments, games, and projects created by leading science centers. Search by keyword, topic, cost, or age to find your next engaging learning experience.

**Highlights:** Hands-on STEM activities, Searchable activity collection, Filter by topic, cost, and age, Created by science centers, Blog with fresh ideas, Suitable for all ages

**Features:** macOS Compatibility

**In-app purchases:** none


### STEM FLEX

[App page](https://appshunter.io/ios/app/stem-flex/id6744830195)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Howtosmile free?

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

### Is STEM FLEX free?

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

### Do Howtosmile or STEM FLEX have ads?

Neither Howtosmile nor STEM FLEX shows ads.

### Which is updated more often, Howtosmile or STEM FLEX?

Howtosmile ships an update every 21 months, and STEM FLEX every 5 days. Most recently, Howtosmile was updated on October 23, 2026 and STEM FLEX on October 6, 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.*