# Trigonometry Quick Reference vs 555 Timer & Oscillators Pro

The clearest difference is price: Trigonometry Quick Reference at $0.99 against 555 Timer & Oscillators Pro's $4.99. Trigonometry Quick Reference also leads on iOS requirement (12.0 vs 16.0). 555 Timer & Oscillators Pro's advantage is update cadence (every 3 months vs every 8 months) and device support (3 vs 1). On ads and in-app purchases there is nothing between them.

Trigonometry Quick Reference costs $0.99 and 555 Timer & Oscillators Pro $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Trigonometry Quick Reference ships an update every 8 months, 555 Timer & Oscillators Pro every 3 months. The most recent releases landed on June 8, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Trigonometry Quick Reference | 555 Timer & Oscillators Pro |
| --- | --- | --- |
| Price | **$0.99** | $4.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/trigonometry-quick-reference/id689382174/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 3 months** |
| Monetization | Paid | — |
| Size | 10 MB | 22 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | iPad | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Ventura Educational Systems](https://appshunter.io/developer/371324172) | [ALG Software Lab](https://appshunter.io/developer/1650561236) |

## What reviewers say

### Trigonometry Quick Reference

[App page](https://appshunter.io/ios/app/trigonometry-quick-reference/id689382174)

This app offers a concise overview of fundamental trigonometry concepts, including sine, cosine, tangent, and inverse functions. It serves as a quick reference tool for students to review key ideas and test their understanding with quizzes.

**Highlights:** Overview of basic trigonometry concepts, Explanations of sine, cosine, and tangent, Information on inverse functions, Unit circle, ranges, and domains, Quizzes to measure understanding, Detailed explanations on key topics

**Features:** macOS Compatibility

**In-app purchases:** none


### 555 Timer & Oscillators Pro

[App page](https://appshunter.io/ios/app/555-timer-and-oscillators-pro/id6504415162)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Trigonometry Quick Reference free?

Trigonometry Quick Reference costs $0.99, with no in-app purchases.

### Is 555 Timer & Oscillators Pro free?

555 Timer & Oscillators Pro costs $4.99, with no in-app purchases.

### Do Trigonometry Quick Reference or 555 Timer & Oscillators Pro have ads?

Neither Trigonometry Quick Reference nor 555 Timer & Oscillators Pro shows ads.

### Which is updated more often, Trigonometry Quick Reference or 555 Timer & Oscillators Pro?

Trigonometry Quick Reference ships an update every 8 months, and 555 Timer & Oscillators Pro every 3 months. Most recently, Trigonometry Quick Reference was updated on June 8, 2026 and 555 Timer & Oscillators Pro on September 24, 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.*