# STEM at SFA vs Calculate84

The clearest difference is in-app purchases: STEM at SFA at none against Calculate84's 6. STEM at SFA also leads on ads (none vs shown) and review sentiment (100% vs 75%). Calculate84's advantage is update cadence (fortnightly vs every 6 months) and ratings volume (54K vs 7). On price and device support there is nothing between them.

Both are free to download. Calculate84 sells 6 in-app purchases, starting at $2.99 per month. STEM at SFA asks for nothing beyond the download.

STEM at SFA holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Calculate84 has 54K ratings behind it against 7, so its average is the more settled of the two. Written reviews point the same way: 100% of STEM at SFA's written reviews are positive against 75% of Calculate84's.

STEM at SFA ships an update every 6 months, Calculate84 fortnightly. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | STEM at SFA | Calculate84 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/stem-at-sfa/id1097369804/reviews)** | [4.8 (54K ratings)](https://appshunter.io/ios/app/calculate84/id1459712793/reviews) |
| Number of ratings | 7 | **54K** |
| Positive reviews | **100.0% of reviews** | 74.6% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Fortnightly** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | — | **#107** |
| Size | 30 MB | 71 MB |
| Requires iOS | **8.0** | 18.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 12+ |
| Developer | [Elemental Software, LLC](https://appshunter.io/developer/413024474) | [Century Light LLC](https://appshunter.io/developer/1459712792) |

## What reviewers say

### STEM at SFA

[App page](https://appshunter.io/ios/app/stem-at-sfa/id1097369804)

Engage with professors on science, technology, engineering, and math topics. Explore the outdoors with a GPS-based activity feature.

**Highlights:** Ask professors questions, STEM subject focus, Outdoor GPS activity, Interactive learning

**Features:** macOS Compatibility

**In-app purchases:** none


### Calculate84

[App page](https://appshunter.io/ios/app/calculate84/id1459712793)

**Currently charting:** #107 Top Free · Education (US App Store)

This app offers a modern graphing calculator experience on your iPhone. It features fast, interactive touch-screen graphing, scrollable windows, and intelligent error messages for a more intuitive user experience. Designed to be a usable alternative to physical graphing calculators.

**Highlights:** Fast, interactive touch-screen graphing, Scrollable windows, Intelligent error messages, Intuitive interface, Designed for TI-84 users

**Features:** Family Sharing, Vision Pro support

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Pro Subscription | $2.99 | per month |
| Annual Pro Subscription | $6.99 | per year |
| Lifetime Subscription | $6.99 | one-time |
| Lifetime Subscription | $9.99 | one-time |
| Lifetime Subscription | $12.99 | one-time |
| Lifetime Pro Subscription | $29.99 | one-time |

**What reviewers like**

- 👍 Identical to TI-84 calculator
- 🚀 Seamless and intuitive user experience
- 💰 Affordable alternative to physical calculator
- 📱 Convenient to have on phone
- 🔍 Comprehensive functionality matching physical calculator

**What reviewers complain about**

- 🐛 Occasional bugs and crashes
- 🔍 Missing some advanced features like regression types
- 🔒 Previous purchases removed without warning
- 💰 Subscription model can be expensive
- 📺 Intrusive ads in free version

**Reported bugs**

- Crashes when using 2-sample T/Z interval functions
- Incorrect results for inverse trig functions
- Issues with graphing parabolas and tracing points
- Regression equation not displayed correctly

**Requested features**

- Add TVM solver functionality
- Implement more regression types
- Allow disabling of ads for free users
- Restore previous purchase benefits
- Optimize for mobile experience instead of emulating physical calculator


## Frequently asked questions

### Is STEM at SFA free?

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

### Is Calculate84 free?

Calculate84 is free to download, with in-app purchases available.

### Which has better reviews, STEM at SFA or Calculate84?

STEM at SFA is rated higher. STEM at SFA averages 5.0 out of 5 from 7 ratings, while Calculate84 averages 4.8 from 54K ratings.

### Do STEM at SFA or Calculate84 have ads?

Calculate84 shows ads; STEM at SFA does not.

### Which is updated more often, STEM at SFA or Calculate84?

STEM at SFA ships an update every 6 months, and Calculate84 fortnightly. Most recently, STEM at SFA was updated on October 24, 2026 and Calculate84 on October 27, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*