Comparison

onetest assessment vs STEMulator

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

onetest assessment

Features
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What is onetest? onetest is a rapid digital assessment that gives a snapshot of a child’s level in literacy and numeracy. It gives both an overall score and scores for individual subskills in literacy and numeracy. Who is it for? onetest is for use by Ministries of Education, teachers, researchers and implementation partners. Ultimately though, onetest is for the child. When key stakeholders can rapidly determine children’s literacy and numeracy levels, appropriate action can be taken to make a change that will improve children’s learning outcomes as soon as possible. The goal of onetest is to bring positive change for the child and their learning outcomes, by identifying which interventions are working, whether that’s on a national level or within a single classroom. Languages onetest is currently available in: Chichewa, Swahili, French for West and Central Africa, Portuguese for Mozambique, International English and American English. More languages will follow. How has onetest been developed and tested? onetest has been developed in-house at onebillion, with input from education experts and with our years of experience developing learning solutions that work for the child. Each localisation is created with input from local pedagogy experts to ensure quality is maintained in each new language. We are working with research partners to validate onetest against existing assessments to ensure accuracy.

About

STEMulator

Features
Read full description

Calling all teenagers and younger. A virtual world full of informative animations on all things STEM (Science, Technology, Engineering & Mathematics), from pumping human hearts to power station turbines, microbes to mountains, farming to factories. How does it work? How is it made? What career and subject choices? Our simple visual navigation system allows you to explore the world at leisure. Get behind the scenes. Still in its infancy, we're hungry for additional content. Think Wikipedia. No in-app purchases required. We’re sharing our knowledge. The STEMulator is for sharing.

Screenshots

onetest assessment4 screens
STEMulator1 screens

Verdict

The call

The clearest difference is iOS requirement: onetest assessment at 9.3 against STEMulator's 15.1. On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

onetest assessment ships an update every 14 months, STEMulator every 9 months. The most recent releases landed on September 9, 2026 and May 19, 2026 respectively.

Scorecard1 real difference · 5 level
onetest assessment versus STEMulator: the parameters behind the verdict, then further details
Parameteronetest assessmentSTEMulator
PriceFreeFree
Update frequencyEvery 14 monthsEvery 9 months — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.3 — better15.1
Further details — not scored
Size83 MB35 MB
Age rating4+17+
DeveloperonebillionSTEMulator

In-app purchases

None

onetest assessment

No in-app purchases

None

STEMulator

No in-app purchases

Questions

Is onetest assessment free?
onetest assessment is free to download, with no in-app purchases.
Is STEMulator free?
STEMulator is free to download, with no in-app purchases.
Do onetest assessment or STEMulator have ads?
Neither onetest assessment nor STEMulator shows ads.
Which is updated more often, onetest assessment or STEMulator?
onetest assessment ships an update every 14 months, and STEMulator every 9 months. Most recently, onetest assessment was updated on September 9, 2026 and STEMulator on May 19, 2026.

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