Astra AI answers school and university questions step by step across thirteen named subjects, adds photo-based solving, and rehearses exams both aloud and in writing. Run by a Slovenian operator under GDPR, on web, iOS and Android.
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Astra AI is a subscription study companion that turns your own notes, slides and past papers into a personalised study plan, reached through a browser or a native mobile app. The distinguishing move is that it does not stop at the answer — it works the problem in stages and, at the top tiers, will examine you on the material afterwards.
The operator is a Slovenian company registered in Ljubljana, which places the service under EU consumer and data protection law by default. That origin also explains the product's shape. Independent reporting traces it to a Slovenian maths-explainer website founded in 2013, rebuilt in 2023 into a full AI tutor covering maths, physics, chemistry, English and German. A national startup competition named the company Slovenia's best startup of 2025, judged on innovation and growth potential.
The headline promise is a refund if a grade does not improve by at least two levels, and the vendor attaches yet another audience figure to that same sentence. Treat that as a marketing commitment whose exact conditions are not published alongside it; the refund terms that are published defer to consumer law rather than spelling out how the guarantee is assessed.
One inconsistency is worth flagging before anything else, because it affects how much weight the site's own numbers deserve. Three different audience figures sit on the same page at the same time: the page metadata puts it at more than 10 million satisfied students, the guarantee line says over 15 million, and the visible counter reads over 12 million. The 10 million figure is only a coarse lower bound and sits comfortably under both of the others, so it does not conflict with them. The three figures differ in precision and in the context they are used in, so read them as a marketing order of magnitude rather than a stable user total. Read the whole set as marketing scale, not as a measured user base.
Three named modes divide the work: Exam Prep for targeted revision, Solver Mode for immediate homework help, and Socratic Mode for working through a topic in depth. The split matters because the same question produces a different interaction in each. Solver Mode is the fast path when you need the method now. Socratic Mode is slower by design, questioning rather than telling.
Photo input feeds all of this — snap any question and it is walked through step by step rather than returned as a single result. On the maths subject page the same entry point accepts a typed problem as well as a photo.
This is the part of the product with the least direct competition. The vendor offers spoken practice with realistic oral exams alongside a full timed written mock, and states that both are graded. For anyone facing a viva, an oral language assessment or a defence, rehearsing the format matters as much as knowing the content, and both formats target the gap between recognising material and producing it under pressure.
Thirteen subjects are named in the site's own subject navigation: maths, chemistry, physics, German, biology, Spanish, geography, history, economics, computer science, philosophy, psychology and French. The vendor's own answer to the coverage question is broader than that list, describing all major subjects and stating that one plan covers every subject and exam you add. The app store listing describes fourteen subjects and adds that lessons are aligned to the official curriculum of the user's country — a claim worth testing against your own syllabus early, since curriculum alignment is easy to state and hard to verify from outside.
Paid tiers add quizzes, flashcards and podcast-style material generated from the subject at hand, which turns the tutor into a revision system rather than only a question-answering service.
Setting an exam date and adding your own notes, slides, past papers or photos produces a topic-by-topic revision plan built around that material rather than a generic syllabus. This is the most specific workflow the product offers, and the sequence is short.
Match the mode to what is actually blocking you. Stuck on tonight's problem set with a deadline tomorrow — Solver Mode. Understood the mechanics but not the reasoning behind them — Socratic Mode, which will make you articulate the idea rather than hand it over. Two weeks from an exam with a stack of material — Exam Prep, which sequences the work.
The two exam formats are the feature most likely to be underused, because rehearsing feels harder than reviewing. That difficulty is the point. Sitting a timed written mock surfaces what you cannot retrieve under pressure, which is different from what you cannot recognise on a page. The oral format adds a second dimension, since explaining aloud exposes gaps that silent reading conceals.
The service is built for this group, and the constraint that governs it is legal rather than technical. Children under 15 may use the service, but parental consent is mandatory before they do. In practice that means the account and the subscription belong to an adult, which the terms reinforce by requiring a parent or guardian to enter into or approve any subscription for a user who cannot contract on their own.
Parents should also read one sentence in the terms directly. The terms also position the product as a support tool that replaces neither parental supervision nor a teacher's pedagogical judgement. That is the vendor drawing its own boundary, and it is a reasonable answer to the question of whether this substitutes for school.
The subject list reaches university level, and the exam rehearsal formats fit that stage well — vivas and oral defences are more common in higher education than in school. The counterweight is the accuracy disclaimer, which matters more as material gets more specialised.
The clearest fit is anyone with a fixed date and a defined body of material. The upload-and-schedule workflow is built for exactly that, and the mock formats give a way to measure progress rather than guess at it.
Anyone who needs verified, citable accuracy — the terms disclaim it explicitly. Anyone wanting a free tool, since the free tier is deliberately narrow. And anyone whose institution restricts AI assistance on assessed work, which is a policy question the product cannot answer for you.
The product ships as a browser application plus native builds for iOS and Android, with the iOS version requiring iOS 15.0 or later. Reach is broad: the iOS listing names thirty-eight interface languages, and the site's own sitemap index carries thirty-seven language or regional sections.
Scale is easiest to read from the Android listing, which reports more than five million downloads against 97,700 reviews. The iOS listing shows 4.8 out of 5 across 1,500 ratings. Both are directional signals about adoption rather than evidence about any particular feature.
Two paid tiers exist and they separate almost entirely on volume rather than on which features are unlocked. Plus is the ordinary plan; Sigma exists for people who hit the Plus ceiling.
| Tier | Monthly | Usage relative to the tier below | Model | Speed | Also included |
|---|---|---|---|---|---|
| Free | $0 | baseline | standard | standard | a few questions to try the product |
| Plus | $24 | 1300x more daily AI usage | 1.4x smarter | 2x faster | quizzes, flashcards, podcasts, mock and oral exams, photo solving, focus mode |
| Sigma | $80 | 8x more than Plus | smartest available | priority even at peak | early access to new features |
The Plus benefit list also carries the grade guarantee as a line item of its own — improve grades or get a full refund. Annual billing is offered alongside monthly with a stated saving of 58%. The iOS listing shows the same structure in euros — €24.00 monthly and €119.99 yearly for Plus, €80.00 monthly for Sigma — along with credit packs from €15.00 to €99.00 for users who prefer to buy usage outright.
Subscriptions run monthly or yearly and renew on their own until cancelled from the profile settings. After cancellation, access continues to the end of the paid period. Refunds defer to the conditions on the platform and, above those, to whatever consumer law grants in your jurisdiction.
The free tier is an evaluation window rather than a usable plan, and the vendor has said so publicly when answering reviewers. Multiple store reviewers describe the same boundary from different angles: free questions running out quickly, imported material unlocking only the first level of the first lesson, and extended sessions prompting for a subscription. The vendor's replies confirm the design rather than dispute it — a few free questions to try, full access on subscription.
That makes the comparison against alternatives largely a pricing question. Photo-solving homework tools occupy the same space at lower monthly cost, and some general study assistants are free. What is harder to find elsewhere is the exam rehearsal pairing — a timed written mock plus a graded spoken exam — which is the reason to pay a premium here rather than the step-by-step explanation, which is common.
The operator states plainly that it cannot guarantee the complete accuracy, completeness or currency of every answer the AI returns. For a tutoring product this is the limitation that matters most, because a confidently wrong explanation is worse than no explanation for a student who cannot yet tell the difference. Everything the app produces should be treated as a draft to check against a textbook or a teacher.
A second clause draws the pedagogical boundary: the product is described as supporting learning, not as standing in for supervision or teaching.
Availability is qualified as well. The operator says the platform is generally available around the clock but does not guarantee continuous or error-free operation, and reserves the right to interrupt access for maintenance, usually at night or on weekends.
Two commercial constraints deserve attention. The free tier ends quickly enough that evaluation is genuinely limited, as multiple reviewers report and the vendor confirms. Access is granted as a non-exclusive, non-transferable and time-limited right, and generally for non-commercial purposes. A tutoring business therefore cannot build a paid service on top of a personal subscription.
On uploads, responsibility sits with the user: you warrant that you hold the rights to any material you upload, and you carry the liability if uploaded content infringes someone else's copyright. For students uploading textbook scans or a teacher's handouts, that clause is worth reading before it becomes relevant.
Finally, the site's own figures disagree with each other, which is a reason to discount the marketing numbers generally rather than a defect in the product itself.
Processing is declared under the GDPR (Regulation (EU) 2016/679) and Slovenia's ZVOP-2 data protection act. The rights that follow are enumerated individually: access, rectification, erasure, portability, restriction of processing, objection, and complaint to a supervisory authority — with a stated ten-day response commitment.
The provision that matters most for this product concerns minors. Under-15s are admitted only once a parent or guardian has given consent, and the vendor states it does not knowingly collect their data without it, using verification methods to confirm the consent was granted. Parents are also advised to monitor their children's use.
One documentation flaw is worth knowing: the privacy policy opens by naming a different website address than the current site, a leftover from the product's earlier domain. It does not change the substance of the policy but it does show the legal documents trail the product.
Thirteen are named on the home page — maths, chemistry, physics, German, biology, Spanish, geography, history, economics, computer science, philosophy, psychology and French — and users can create any subject not listed. The app store listing says fourteen and adds that lessons align to the official curriculum of your country.
Solver Mode gives immediate homework help, working a problem to its answer. Socratic Mode explores a subject in depth by asking rather than telling, which is slower but aimed at understanding instead of completion. Exam Prep is the third mode, organising revision against a date.
Yes. You answer aloud, it asks follow-up questions, and it grades you at the end, with the aim of rehearsing under something close to real conditions. A written mock exam runs the same idea against a time limit and then reports where you were weakest.
There is a free tier, but it is limited to a few questions for evaluation — the vendor states this openly in response to reviews. Plus costs $24 per month and Sigma $80, with annual billing advertised as 58% cheaper. On iOS the same plans appear as €24.00 and €80.00 monthly, with a €119.99 annual option and credit packs.
The service is open to children under 15 only with mandatory parental consent, and the operator states it does not knowingly collect their data without it. A parent or guardian must also enter into or approve the subscription where the child cannot contract. Content ratings are 9+ on iOS and Everyone on Android.
Not without checking. The terms explicitly decline to guarantee accuracy, completeness or currency of AI-generated content, and separately state the product does not replace a teacher's pedagogical judgement. Use it to understand a method, then verify specifics against course material.
Subscriptions renew automatically until cancelled through the profile settings under "Manage subscription". After cancelling, the service stays available until the end of the current monthly or annual period or until the next scheduled payment date. Refunds follow the platform's stated conditions plus any statutory rights in your jurisdiction.
The feature exists — uploading study materials is how Exam Prep builds a plan around your exam date. The terms place responsibility on you: you warrant that you have the rights or legal basis to upload that content, and you carry liability for infringement of third-party rights in what you upload.
