ZAPP
Zap through CS · by CS with ZAK · Android & iOS
The whole site.
In your pocket.
Even offline.
A CAIE pseudocode runner that works with no signal, AskZ that knows what page you're on, 1,600+ flashcards that swipe, every past paper filtered, and an exam planner that counts down in your Cambridge zone's Key Time. Built by ZAK for the students he teaches, and for you.
iOS 17+ · Android 9+No account neededSyncs with cswithzak.com
Assalam o Alaikum
Sara 👋
Paper 2 · Fundamental Problem-solving
Thu 7 May · 09:00 Key Time · 2 h
🔥
12
day streak
⚡
2,140
XP
🎯
84%
weak cards
ZAK suggests
Two's complement — 15 min
You missed 3 of 5 on Tuesday
Due
1,600+
flashcards offline
1,300+
quiz questions
30
topics, every one covered
0
ads. Forever.
Take the tour
Seven screens. Zero fluff.
Every screen does one job a Cambridge CS student actually has. Tap through — these are the real layouts the app ships with.
01 / 07
One screen for the whole week
Your level, the next paper's countdown, today's streak and the topic ZAK thinks you should revise next — before you scroll anywhere.
Assalam o Alaikum
Sara 👋
Paper 2 · Fundamental Problem-solving
Thu 7 May · 09:00 Key Time · 2 h
🔥
12
day streak
⚡
2,140
XP
🎯
84%
weak cards
ZAK suggests
Two's complement — 15 min
You missed 3 of 5 on Tuesday
Due
What's inside
Everything the website does, plus the things only a phone can.
Same content, same interpreter, same AskZ. Then widgets, a camera, notifications and a screen that's always with you.
Offline pseudocode runner
The full 9618 pseudocode guide — records, files, classes, exception handling — runs natively. Trace tables generate as you step.
TYPE Student
DECLARE Name : STRING
DECLARE Marks : ARRAY[1:3] OF INTEGER
ENDTYPE
DECLARE S : Student
S.Name ← "Sara"
OUTPUT LENGTH(S.Name) // 4 — runs offlineAskZ, context-aware
Long-press any paragraph, question or line of code and ask. AskZ knows your level, topic and what you got wrong last week.
Works without signal
Notes, papers, cards and quizzes download once and stay. Progress syncs the moment you're back online.
Reminders that respect you
Assignment deadlines, exam countdowns and a gentle daily nudge at the time you pick. Nothing else. Ever.
Synced with the website
Start a quiz on your laptop, finish on your phone. Weak cards, streaks and XP are the same everywhere.
Home-screen widgets
Days to your next paper, today's card and your streak on the home screen and lock screen — Android and iOS.
Snap a question
Photograph a past-paper question. ZAPP finds it in the bank, shows the mark scheme and lets AskZ walk you through it.
Dark by default
Designed dark first, with a true-black OLED mode. Light mode if you insist. Dynamic Color on Android, Dynamic Type on iOS.
Private by design
No ads, no trackers, no selling anything. Your progress lives on your device and in your own account, nowhere else.
Karachi traffic is now revision time.
Download a topic once and its notes, papers, cards and quizzes live on the phone. The pseudocode interpreter is compiled into the app, so running and tracing code needs no server. When you're back online, your progress syncs quietly with the website.
- Topic packs: notes + papers + cards + quiz, one tap, a few MB each
- Progress, streaks and weak cards merge across devices, never overwrite
- Past papers keep your handwritten marks and self-marking totals
- AskZ conversations resume where you left off on the website
Playground
squares.pseudo
Trace table
Aeroplane mode
still runs
Synced
laptop ↔ phone
Glanceable
You'll see the countdown before you see Instagram.
Widgets for the home screen and lock screen on both platforms. One notification a day, at the time you choose, and deadline nudges you set yourself. That's the whole list.
9618 Paper 2 · Zone 4
23days
Thu 7 May · 09:00 Key Time
Name the three components of a von Neumann CPU.
Tap to flip · streak 🔥 12
ZAPP
now
Assignment 7 · Recursion is due tomorrow. 20 minutes tonight?
ZAPP
8:00
Daily nudge: 10 weak cards are waiting. You've done 12 days straight.
ZAPP
Sat
Mock Paper 1 at Zatians is in 2 days. Your planner moved SQL to Friday.
Notifications are opt-in and can be switched off in one tap. No streak guilt-trips, no marketing.
Android & iOS
Native on both. Second-class on neither.
One codebase, two proper apps. Each one uses what its platform does best — and the core is identical, down to the pseudocode interpreter.
iOS
iOS 17 or later · iPhone & iPad
- Lock Screen & StandBy widgets
- Dynamic Island exam countdown
- Live Activities during a timed quiz
- Shortcuts: “Hey Siri, ask ZAK…”
- Handoff to the website
Android
Android 9 or later · phones & tablets
- Home-screen & lock-screen widgets
- Material You dynamic colour
- Quick Settings tile for AskZ
- Share sheet: send any text to AskZ
- Instant App for past-paper links
| Feature | iOS | Android |
|---|---|---|
| Offline notes, papers, cards, quizzes | ||
| Pseudocode runner + trace tables | ||
| AskZ with page context & voice | ||
| Exam planner with Cambridge zones | ||
| Home-screen widgets | ||
| Lock-screen widgets | ||
| Live countdown in Dynamic Island | ||
| Quick Settings tile | ||
| Snap a question (camera) | ||
| Tablet split-view layout |
Roadmap
Where it is, where it's going.
Honest status, updated as it moves. The beta is real; the store listings go live when it's good enough for exam season.
- 1Now
Private beta
ZAK's own class groups are testing on TestFlight and Play internal testing. Bugs are being squashed weekly.
- 2Next
Open beta
Any student can join from this page. Sync, widgets and the offline runner ship in this phase.
- 3Then
Store launch
Public release on Google Play and the App Store, timed before the May/June series.
- 4Later
Snap a question, teacher mode
Camera search of the past-paper bank, and a mode for teachers to assign quizzes and see class heat-maps.
Be the first to break it.
Beta builds go out over TestFlight and Google Play internal testing. Tell ZAK your level and phone, and you're in the next wave. Bug reports earn a shout-out in the app's credits.
Built with students, not just for them.
ZAPP is React Native + TypeScript on top of the website's open content. If you're a ZAK student who codes, there is real work: screens, the runner's debugger, widgets, translations. Your name ships in the app.
- Pair sessions with ZAK on the codebase
- A real repo, real reviews, a real line on your university application
- Stickers. Obviously.
FAQ
Questions students actually ask.
Is ZAPP free?+
Yes — like the website. No ads, no in-app purchases, no premium tier. ZAK's classes and Success Packs are the only things that cost money, and the app never nags you about them.
Do I need an account?+
No. The app works fully without one. Signing in (Google or Apple) only turns on sync between your phone and the website, and you can delete everything with one tap.
Will it work on my old phone?+
iOS 17+ and Android 9+. The pseudocode runner and cards are light; the app is about 35 MB and downloaded topics take a few MB each.
Does the pseudocode runner really work offline?+
Yes. The interpreter is the same one behind the website's playground, bundled into the app. Files, records, classes, exception handling — all of it runs on the device.
Is AskZ available offline?+
AskZ needs internet, because the model runs on ZAK's servers. Everything else — notes, papers, cards, quizzes, the runner and the planner — is offline.
What does the app know about me?+
Only what it needs: your level, which questions you've seen and missed, and your reminder time. No location, no contacts, no ad identifiers. The privacy nutrition label is empty on purpose.
I'm a student who codes. Can I help?+
Please. The app is built with React Native and TypeScript on top of the website's open content. Message ZAK on WhatsApp with what you'd like to work on.
The stores say “coming soon”. What do I use today?+
This website is already an installable app (a PWA). On iPhone: Share → Add to Home Screen. On Android: browser menu → Install app. Progress carries over to ZAPP when it launches.
Can't wait? This site already installs like an app.
cswithzak.com is a Progressive Web App: full-screen, its own icon, works offline for pages you've opened, and your progress carries into ZAPP on launch.
iPhone / iPad
- Open cswithzak.com in Safari
- Tap Share
- Tap Add to Home Screen
Android
- Open cswithzak.com in Chrome
- Tap the ⋮ menu
- Tap Install app