Flashcards that come back
Tap to flip. Cassie brings each card back right before you’d forget it.
Free for students · Philippines & worldwide
Highlight anything.
Highlight anything.
Cassie explains it.
Your AI study buddy for readings, homework and reviewers. Don’t take our word for it — highlight a word on the page here and see what she does.
No account needed
Your notes stay on your device
Phone, web & Chrome
Try it: highlight any word — or tap a bold one
Energy in cells
Every cell in your body needs energy. It gets it through cellular respiration: inside the mitochondria, glucose from your food reacts with oxygen to make ATP, and you breathe out the carbon dioxide that’s left.
Plants run it the other way. With the chlorophyll in their leaves, they use photosynthesis to turn carbon dioxide, water and sunlight into glucose — and the oxygen you breathe.
CASSIE
This is how Cassie works on any website, PDF, slide deck or photo of your notes.
Any websitePDFsGoogle DocsGoogle SlidesPowerPointWord filesPhotos of your notesGraphs & diagramsYour phoneChrome
Any websitePDFsGoogle DocsGoogle SlidesPowerPointWord filesPhotos of your notesGraphs & diagramsYour phoneChrome
The main things
Don’t watch a demo. Use it.
Every tab is a working piece of Cassie. The Labs, 3D space, atlas and puzzles are the real ones from the app, running right here.
In the app she answers anything — these demos are written ahead.
Meet Cassie
She shows you what she’s doing.
Cassie is a cursor with feelings. While you study, she reads, thinks, searches and celebrates with you, so you always know what’s happening.
Tap Cassie to poke her.
Everything else
Small things that add up.
Go on — every card works.
Quiz me
On your lesson, your file, or what you got wrong last time.
Photosynthesis gives off…
Focus timer
25/5, 50/10 — or your own rhythm.
25:00
At your level
The same idea, explained for whoever’s asking.
Photosynthesis turns light energy into chemical energy. In the chloroplasts, chlorophyll captures light to combine carbon dioxide and water into glucose, releasing oxygen: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
Research with real sources
Real papers, organized — then cite them in any style.
Walker, M. P., & Stickgold, R. (2004). Sleep-dependent learning and memory consolidation. Neuron, 44(1), 121–133.
Draw together
A shared board with your classmates — share a code and sketch it out.
Mika is here
She remembers — you decide
What Cassie remembers stays on your device. Forget anything with a tap.
- You’re in Grade 10, Section Rizal
- Fractions trip you up a little
- Biology exam on Friday
- You like examples with basketball
Student or working
Cassie dresses for the job — reviewers for school, reports and emails for work.
Let’s turn chapter 4 into a reviewer with 10 practice questions.
Always in sight
Cassie’s Island shows what she’s doing — even while you read something else.
Reading Module 6.pdf · page 4 of 18
Made for learning, not for test time.
Cassie explains the reasoning, quizzes you, and turns your lessons into reviewers. She’s for readings, homework and review — not for use during a test or quiz.
Because the point isn’t the answer. It’s you knowing it.
Private by design
Your notes are yours.
Account optional
Use Cassie without signing up. Make an account and only your profile, settings and saved quiz mistakes sync — never your chats or files.
On your device
Chats, memory and reviewers are saved in your browser — export a backup any time.
Bring your own key
Power users can plug in a free Groq or Gemini key for unlimited use on the free plan.
Pricing
Student prices. Seriously.
Free forever, no card needed. Upgrade when Cassie becomes part of how you study.
Free
See what Cassie can do. Best for trying it out.
₱0forever
No card needed
Start free
- 20 questions a day — chat, quiz & highlight
- 5 file reviewers a month (PDF, slides, Word)
- 10 pictures a month
- Explore 3D: the human body (all 10 systems, boy & girl) and cells
- Talk with Cassie in Bella’s voice — 30 minutes of listening a month
- Quiz me, Review my mistakes & Teach Cassie
- Board, graphs, focus timer, memory & sync
- Chrome extension: highlight, snip & ask about any page
- 2 research runs a month — real papers & citations
- Unlimited with your own free API key
Most popular
Plus
Study as much as you want. Best for everyday school.
₱149/ month
billed monthly · cancel anytime
Join the waitlist
- Everything in Free
- Unlimited questions*
- 30 file reviewers a month
- 100 pictures a month
- Unlimited voice chat*
- Reads photos, diagrams & handwriting
- Save as Word, PDF or image
- 10 research runs a month
Pro
Everything, unlimited. Best for finals season — every season.
₱499/ month
billed monthly · cancel anytime
Join the waitlist
- Everything in Plus
- Unlimited file reviewers*, including whole books
- Unlimited pictures*
- Unlimited research*: real papers, organized sources & citations
- Smartest models first
- Priority when Cassie is busy
Refer a classmate: when they join, you both get a week of Plus free.
*Unlimited means normal studying by one person, not shared accounts or automated use. A Semester pass is one payment for 5 months — nothing is charged over the break. Paid plans are launching soon — everything on Free works today.
FAQ
Questions, answered.
Is Cassie really free?
Yes, forever, with no card needed: 20 questions a day, 5 file reviewers and 10 pictures a month, plus Explore 3D and talking with Cassie. If you add your own free Groq or Gemini key, you can use Cassie as much as you like.
What can she read?
Any website you highlight or snip, PDFs, PowerPoint and Google Slides, Word files and Google Docs, and photos or screenshots of your notes — including the diagrams and graphs in them.
Does it work on my phone or tablet?
Yes. Open Cassie in your browser and add it to your home screen. For PDFs, Word and PowerPoint, attach the file and tap 📖 Read & highlight: read it inside Cassie and highlight any part. In other apps: on Android, select the words → Share → Cassie. On iPhone and iPad, set up the one-time “Ask Cassie” Shortcut (steps in Cassie → Settings → Use Cassie in other apps). Screenshots and photos of your notes work too. The on-page popup and snipping on a computer come with the Chrome extension.
How do I add Cassie to Chrome?
Download the Cassie extension, then unzip it. Open chrome://extensions, turn on Developer mode (top right), click Load unpacked and pick the cassie-extension folder. Pin Cassie from the puzzle-piece menu and you’re done — no key needed. Works in Chrome and Edge on a computer.
Where do my notes and chats go?
They’re saved in your own browser, not on our servers. Your question and any file you attach are sent to the AI service to get an answer, and that’s it. If you make an account, only your profile, settings and saved quiz mistakes sync. You can export a backup or clear everything at any time.
Can I use Cassie during a test or quiz?
No — and please don’t. Cassie is built for studying: understanding readings, practising, and making reviewers. Using her during a graded test or quiz isn’t what she’s for.
How do I pay from the Philippines?
When paid plans launch you’ll be able to pay in pesos with local options like GCash and Maya, or by card. Everyone else pays in US dollars.
Study with Cassie tonight.
Free, private, and ready on any page you’re reading.
Open Cassie — it’s free Get the Chrome extension