SizeChina vs StoichioAI
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SizeChina
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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.
StoichioAI
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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
Verdict
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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
SizeChina ships an update every 60 months, StoichioAI weekly. The most recent releases landed on November 3, 2026 and October 25, 2026 respectively.
| Parameter | SizeChina | StoichioAI |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 60 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 12.0 — better | 17.1 |
| Further details — not scored | ||
| Size | 23 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Apps Resource Centre, Hong Kong Baptist University | Pang Ka Wai |
In-app purchases
SizeChina
No in-app purchases
StoichioAI
No in-app purchases









