Comparison

SizeChina vs StoichioAI

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

Head to head
About

SizeChina

Features
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The SizeChina database is the first-ever 3D digital database of Chinese head and face shapes. Accurate facial dimensions extracted from the SizeChina database can be accessed from this app, which helps students and professionals alike in designing Chinese-fit consumer products such as glasses, helmets and face masks.

About

StoichioAI

Features
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StoichioAI is for Hong Kong secondary chemistry. Students write calculation steps on a whiteboard. The AI reads the working and asks questions, instead of handing over the answer. It is for students preparing for HKDSE Chemistry and for teachers who need to see how their own groups are doing. The interface, topics and AI replies can be switched between Traditional Chinese and English. English uses Hong Kong DSE chemistry wording and British spelling. Students can: Read an interactive lesson, then try the follow-up calculations Write with Apple Pencil or a finger, or submit a photo from the camera or the photo library Ask for a Socratic hint after a wrong attempt. Spoken feedback is Cantonese in Chinese and English in English Review feedback, past attempts, points, and a learning suggestion based on their own weak spots Teachers can: Create a teaching group and invite students with a join code or a school email See weak topics, common mistakes, and each student’s progress Refresh an AI suggestion for the group or for one student Preview questions and reference answers Topics include reacting masses, concentration, pH, volumetric analysis, standard enthalpy changes, Hess's law, rate of reaction, molar volume of gases, equilibrium constant, shifts in equilibrium, organic synthesis calculations, rate equation, activation energy, atom economy, separation and purification, quantitative analysis, instrumental analysis, and analytical chemistry applications. Sign in with an authorised school email. Points are awarded only the first time an exercise is answered correctly.

Screenshots

SizeChina3 screens
StoichioAI4 screens

Verdict

The call

The clearest difference is update cadence: StoichioAI at weekly against SizeChina's every 60 months. SizeChina's advantage is iOS requirement (12.0 vs 17.1). On price, ads, in-app purchases and device support 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

SizeChina ships an update every 60 months, StoichioAI weekly. The most recent releases landed on November 3, 2026 and October 25, 2026 respectively.

Scorecard2 real differences · 4 level
SizeChina versus StoichioAI: the parameters behind the verdict, then further details
ParameterSizeChinaStoichioAI
PriceFreeFree
Update frequencyEvery 60 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPodiPhone, iPad
Requires iOS12.0 — better17.1
Further details — not scored
Size23 MB27 MB
Age rating4+4+
DeveloperApps Resource Centre, Hong Kong Baptist UniversityPang Ka Wai

In-app purchases

None

SizeChina

No in-app purchases

None

StoichioAI

No in-app purchases

Questions

Is SizeChina free?
SizeChina is free to download, with no in-app purchases.
Is StoichioAI free?
StoichioAI is free to download, with no in-app purchases.
Do SizeChina or StoichioAI have ads?
Neither SizeChina nor StoichioAI shows ads.
Which is updated more often, SizeChina or StoichioAI?
SizeChina ships an update every 60 months, and StoichioAI weekly. Most recently, SizeChina was updated on November 3, 2026 and StoichioAI on October 25, 2026.

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