Thrifty — $99 a year (about $8.25/mo).
Every new account starts free on Lo-Fi. Founding offer: $49 your first year.
Thrifty
$8.25/mo, billed $99/yr. Cancel anytime · 30-day money-back.
Thrifty Semester
One payment. Never renews.
More ways to pay
Thrifty Monthly · $14.95/month
Renews monthly.
Family · $149/year
Up to 3 linked students.
Student · $59/year
18+ with a .edu email.
Every new account starts on Lo-Fi, free forever, no card. Cancel a paid plan anytime · 30-day money-back.
Not ready? Start free on Lo-Fi — free forever, 10 messages a week.
Lo-Fi vs Thrifty — what students actually get
Tap any row for a quick preview of how it works. Start free. Upgrade only when one class isn't enough or finals show up.
| Capability | Student use case | Lo-Fi | Thrifty ★ |
|---|---|---|---|
| Messages | Quick homework questions, concept checks | 10 / week | No weekly limit |
| Courses & syllabi saved | Context-aware help that knows your class | 1 course | Every course |
| File uploads per prompt (PDFs, slides, images) | Summarize readings, study from lecture decks | — | |
| Voice notes | Study while walking to class | — | |
| Image / diagram generation | Visualize bio cycles, physics setups, flowcharts | — | |
| Mock Exam + Flashcards | Timed practice quizzes, spaced-repetition study decks | — | |
| Share-to-Story 9:16 cards | Send classmates a clean answer screenshot | — | |
| Tool-Kit — Tiny Tool code-gen | Generate study utilities, calculators & mini-apps from a prompt | — | |
| Tutor Mode (Socratic) | Learn the material, don't just get the answer | ||
| Chat history | Find that explanation from last week | 30 days | Full semester |
| Chrome extension + mobile app | Study anywhere — laptop, phone, library PC |
Tap any row for a 10-second preview. Both plans include Guide me and the 30-day money-back guarantee.
Every plan, side by side
Every paid plan unlocks the same Thrifty features. They differ only in who pays and how long it lasts.
- Lo-Fi$0
10 messages a week · Free forever
- Thrifty$99/year
~$8.25/mo · parent can pay · Renews yearly
Best value for the school year
- Thrifty monthly$14.95/mo
Cancel anytime · Renews monthly
Short stretches
- Thrifty Semester$39
4 months · one payment · Never renews
One term or exam season
- Thrifty Student$59/year
18+ with a .edu email · Renews yearly
College students paying for themselves
- Family$149/year
Up to 3 students · one parent sign-in · Renews yearly
Parents with more than one student
Family covers up to 3 students linked to one parent account; the parent page shows all of them. Thrifty Student needs an 18+ account signed in with a .edu email. Semester is one payment for 4 months and never renews — it drops to Lo-Fi when it ends.
See what they missed — without reading their chats.
Your own sign-in, on your own phone. Your child makes a code in their Me tab, you enter it once, and you get a read-only page.
- Progress: questions asked and cards practised this week
- Misses: the shaky ideas Sugar is holding, and when each comes back
- Free accounts keep the 15 most recent misses in rotation — older ones are parked, never deleted, and return on Thrifty
- One line by email every Sunday. No homework answers, nothing they wrote
Ages 13–17 need a parent’s email approval before the account opens. We never ask a child for a card.
Is there an AI homework app where the parent pays, not the student?
Yes — LemonSugar Ai. A parent buys Thrifty at $99 a year on their own phone, and the student account never asks a kid for a card. Under-18 accounts have checkout turned off entirely; a parent approves the account by email first. Students on Lo-Fi keep asking for free, forever.
What the year buys is the loop, not a pile of models: Guide me asks questions instead of handing over the answer, teach back makes the student explain it, and every miss comes back on schedule until it sticks. Homework that ends. Misses that return.
Upgrade FAQ
The honest answers we'd want before paying $99 a year.
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