StoichioAI vs Star Explorer

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.

Point your iPhone at the night sky and instantly see what you're looking at. Star Explorer names stars, planets, constellations and the Moon in AR, and tells you what's worth seeing tonight from where you are. No sign-up needed to start. The star catalog, sky map and astronomy assistant work offline, so they keep working at dark-sky sites with no signal. WHAT YOU CAN DO - AR star finder: hold up your phone to identify stars, planets and constellations, with comet and meteor-shower layers - Night sky map: a live all-sky chart you can move forward or back in time; search 8,900+ stars, all 88 constellations and all 110 Messier objects - Tonight's sky: Moon phase, visible planets and observing conditions for your location and weather - Sky events: meteor showers, planet oppositions and every solar and lunar eclipse from 2027 to 2030, with reminders - Offline astronomy assistant: ask questions and get an observing plan without a connection - Red-light night mode that protects your night vision - Tonight's Sky widget for your Home Screen - Bite-size astronomy lessons with quizzes, and a stargazing trip planner - Made for iPhone and iPad, including the iPhone Duo inner display Free forever: AR star finder, sky map, sky events, offline assistant, lessons, night mode and widget. Optional purchases: - Pro, all features, lifetime: one-time purchase that unlocks the deep-sky catalog, astrophotography assistant, cloud AI and photo identification - Observing Tools, lifetime: one-time purchase that unlocks the deep-sky catalog and astrophotography assistant - Cloud AI monthly / yearly subscription: unlocks cloud AI answers and photo identification Auto-renewing subscriptions: the subscription period is 1 month or 1 year, and payment is charged to your Apple ID account when you confirm the purchase. The subscription renews automatically at the same price unless auto-renew is turned off at least 24 hours before the end of the current period. Manage or cancel any time in Settings > Apple ID > Subscriptions. The price shown on the App Store purchase confirmation is final. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://star.xinghebit.com/privacy/ Sky data, weather, travel routes and AI answers may contain errors and are not navigation, weather or safety guarantees. Check official sources before observing outdoors. Never look at the Sun through a camera, binoculars or telescope without a certified solar filter.