Solved Math Privacy Policy
Last updated: 2026-11-11. Controller: Sergiy Bondarev, IČO 23604280, Bachmačská 691, 280 02 Kolín, Czechia (“we”, “us”). Contact: privacy@halfpast.io.
The short version
- Solved Math solves maths problems. Many are solved on your phone and never leave it.
- When you scan a photo or ask for an AI solution, we send that photo or problem to our AI provider, Anthropic, to read and solve it. Not your name, not your e-mail.
- The app is for people 13 and over. If your app store does not tell us your age range, we ask it once (under 13, 13–15, 16–17, 18 or older). Everyone under 18 gets teen protections: ads are never personalised and there is no profiling.
- If you are 18 or over, ads may be personalised and we collect usage analytics (never your problems, photos or answers): outside the EEA, the UK and Switzerland unless you turn it off, inside them only if you agree.
- Your history of solved problems stays on your phone. Only if you sign in with Google and leave Sync history on do we keep a copy with your account, so it appears on your other devices. Photos are never synced.
- We keep as little as we can, for as short a time as we can, and you can delete your data in the app or on the web at any time.
- AI answers are labelled and can contain mistakes.
1. Children under 13
Solved Math is not intended for children under 13, and we do not knowingly collect personal information from them.
- Where Google Play (or, later, the App Store) provides an age range for your account because a law requires it, the app checks it before it connects to any of our services. Otherwise the app asks once for your age range (under 13, 13–15, 16–17, 18 or older; never your birth date), also before it connects to anything. If the range is under 13, the app shows that it is for ages 13 and up and does not start any service that collects data (no account, no ads, no analytics, no crash reports, nothing sent to us). An “under 13” answer is not stored, only the date until which the app stays closed.
- If we learn that we have collected personal information from a child under 13, we delete it promptly and close the account.
- Parents and guardians: if you believe your child under 13 has used Solved Math, write to privacy@halfpast.io. If you can, include the Support ID shown in the app under Settings → Privacy. We will delete the account and its data, normally within 30 days.
2. Teenagers (13–17) and why everyone gets teen protections
We apply these protections to every user unless your app store tells us, or you told us, that you are 18 or over (for adults, see “Usage analytics” in §3 and §5):
- Ads are never personalised and are limited to content suitable for teenagers. In the EEA, the UK and Switzerland we tell Google to treat you as under the age of digital consent, so Google serves only limited ads without consent-based storage on your device.
- No profiling and no marketing based on your data. We never sell your data. Outside the EEA, the UK and Switzerland we do count, without your content, which features are used and which of our ads brought you to the app (so we can tell which ads work). This never personalises the ads you see, and you can turn it off in Settings → Privacy → Usage analytics.
- Optional processing stays off in the EEA, the UK and Switzerland: we do not ask a user who may be under their country's digital-consent age (for example 16 in Germany, Ireland or the Netherlands, or 14 in Italy and Spain) to consent to optional processing such as crash reports or analytics, and that processing stays off.
- An AI notice instead of a consent form: before your first AI use the app tells you what is sent to the AI and that answers can be wrong. We process what you send because it is necessary to give you the service you asked for. You can turn AI features off at any time in Settings → Privacy.
- Purchases go through Google Play or the App Store, including their family and parental-approval controls.
3. What we collect, why, and on what basis
| What | When | Why | Legal basis (EEA/UK) | Kept for |
|---|---|---|---|---|
| Problems you type (maths, the words of a word problem) | when you ask for an AI solution | to solve it, check the answer, refund failures, prevent abuse | contract | AI job record 90 days; see §6 for the shared answer cache |
| Photos you scan | when you scan | to read the problem (cropped and downscaled on the phone; location and camera data removed) | contract | never stored by us; the transcribed text 7 days |
| Anonymous account id (Firebase) | first online feature | to keep your credits, purchases and limits | contract | until you delete your data |
| Device identifiers: a one-way hash of the Android device id, the Firebase installation id, App Check / Play Integrity tokens | first online feature | fraud and abuse prevention (free daily limits per device, genuine-app checks) | legitimate interest (security, fair use) | device counters up to 400 days, unlinked from you after deletion |
| Purchases: order ids, purchase tokens, product, dates | when you buy | to grant credits and Plus, handle refunds, keep accounting records | contract; legal obligation | as long as tax and accounting law requires, unlinked from you after deletion |
| Ad records: that you watched a rewarded ad, ad unit, time | Free plan, when you watch | to give you the free use you earned and prevent fraud | contract; legitimate interest | 30 days |
| Region: a two-letter country code (the strictest of your SIM, network and phone-region countries) and your time zone | online features | to apply the right local rules and daily limits, and to keep online features off where we do not offer them | legitimate interest; legal obligation | on the account until deletion |
| Age range from your app store (only where a law makes the store provide one) | app start | to decide whether the app may be used and which protections apply | legal obligation | on your phone, and as an age band (adult or minor, never a birth date) on the account until deletion; never used for ads or profiling |
| Age range you tell us (only when your app store gives none: 13–15, 16–17 or 18 or older; “under 13” is not kept) | once, after the welcome screen | to decide whether the app may be used and which protections apply | legal obligation; legitimate interest | on your phone until you delete your data, and as an age band (adult or minor) on the account until deletion; never used for profiling (an 18+ answer lets ads be personalised where you allow it) |
| Google account e-mail and id | only if you choose “Back up & sync” | to restore your credits on another device | contract | until you delete your data or sign out |
| Synced history: the problems you solved (the maths or the words you typed or scanned, as text), their topic, dates, stars and deletions, and the solutions shown to you | only if you sign in with Google and “Sync history” is on (on by default after sign-in; Settings → Account) | to show your history on every device signed in to your account | contract | until you delete the item (deletions sync too) or delete your data; turning sync off stops syncing but keeps the copy for your other devices |
| Crash reports (Firebase Crashlytics): device model, OS version, app version, the technical trace of the crash | when the app crashes. Outside the EEA, the UK and Switzerland: on unless you turn them off. In the EEA, the UK and Switzerland: only with your consent, and never for a user who may be under the digital-consent age | to fix bugs | consent (EEA/UK/CH); legitimate interest elsewhere | 90 days |
| Usage analytics (Google Analytics for Firebase): which features you use (for example “solved on the phone”, “scan read”, “ad watched”, “purchase verified”), counts, timings, app version, device model and a random app-instance id; never the problems, photos or answers | outside the EEA, the UK and Switzerland: on unless you turn it off (Settings → Privacy → Usage analytics). In the EEA, the UK and Switzerland: only for users who are 18 or over, and only as far as they agreed in the consent form (Settings → Privacy → Ad choices); never for a user who may be a teenager | to improve the app and to measure which of our ads bring real users (Google Ads); for users 18 and over who allow it, also to personalise ads with Google | consent (EEA/UK/CH); legitimate interest elsewhere | 14 months |
| Support messages | when you write to us | to answer you | legitimate interest; contract | 2 years |
| In-app feedback (Settings → Send feedback, or “Tell us more” on a solution): the category and message you write; the problem you chose to attach (as you entered it) and its solution id; a small copy of the scanned photo only if you tick it; your e-mail only if you give one; added automatically: app version, device model (never a device id), app language and your Support ID | only when you press Send (kept on your phone until you are online) | to fix bugs and wrong answers, answer you if you asked, and prevent abuse | legitimate interest | 180 days |
We do not collect your name (unless you sign in with Google), contacts, precise location, microphone, or photos you do not choose to scan. Your history of solved problems stays on your phone, unless you sign in with Google and keep Sync history on: then a copy of it (text only, never photos or thumbnails, and nothing about payments) is stored with your account so your other devices can show it. If you sign out, the history on that phone stays there and stops syncing.
4. AI processing (Anthropic)
- When you scan a photo or ask for an AI solution, the photo or problem text is sent to Anthropic, PBC (our AI service provider, acting on our instructions) to read and solve it. Anthropic is the only AI provider we use.
- We do not send your name, e-mail, account id, device id or the photo's location data. Each request contains only the problem, your language, and the instructions the app always uses.
- Anthropic does not use this data to train its models and keeps it only as long as its commercial terms allow (it deletes them within 30 days; a request its safety systems flag under its usage policy is kept for up to 2 years, and data may be kept longer where the law requires).
- The AI is instructed to stay on maths, to refuse unrelated or unsuitable requests, never to ask for personal information, and never to pretend to be a person.
- AI-produced solutions are labelled and can contain mistakes: check important results.
5. Advertising (Google AdMob)
- On the Free plan you can choose to watch rewarded ads from Google AdMob to unlock free AI uses. Plus has no ads. The app never starts the ads service for a user whose store age range is under 13.
- Ads are always limited to content suitable for teenagers.
- Under 18 (or if the app does not know you are 18 or over): ads are never personalised. In the EEA, the UK and Switzerland, we tell Google that you may be under the age of digital consent, so Google shows only limited ads: no personalisation and no consent-based storage on your device.
- 18 and over: outside the EEA, the UK and Switzerland, ads may be personalised by Google. In the EEA, the UK and Switzerland, the app shows Google's consent form, and ads are personalised only if you agree there; you can change your choice at any time in Settings → Privacy → Ad choices.
- AdMob receives device information such as the advertising ID and IP address to deliver and measure ads and to prevent fraud, under Google's own terms. You can reset or delete your advertising ID in your phone's settings. See how Google uses information from apps.
- When you finish a rewarded ad, Google sends us a signed confirmation with your anonymous account id, so we can give you the free use.
6. Firebase and Google Cloud
We run our online services on Google Firebase / Google Cloud in the EU (europe-west1, Belgium): Firebase Authentication (anonymous accounts; Google sign-in only if you choose it), Cloud Firestore and Cloud Functions (credits, purchases, AI jobs, limits, and your synced history if you use Sync history; only you, signed in with Google, can read or change it), Firebase App Check with Play Integrity (checks that requests come from the genuine app), Firebase Remote Config (feature switches; no personal data), Firebase Crashlytics (crash reports), Google Analytics for Firebase (usage analytics, as described in §3) and Google Play Billing (purchases; we never see your card).
A shared answer cache stores the text of solved problems and their verified solutions without any link to you, so the same problem can be answered faster for everyone. Problems that look like they contain contact details (e-mail addresses, phone numbers, links, long numbers) are never cached.
7. Who we share data with
We do not sell personal information. We share it only with our service providers, who process it on our instructions (Anthropic for AI; Google for Firebase, Google Cloud and Play Billing), with Google for rewarded ads (AdMob, §5) and usage analytics (§3), and with authorities when the law requires it. Data of users who may be under 18 is never used to personalise ads.
International transfers. Anthropic processes data in the United States, and Google may process data outside your country. Transfers rely on the European Commission's Standard Contractual Clauses (with the UK addendum) or on the EU-US Data Privacy Framework where the provider is certified.
8. How long we keep data
| Data | Kept |
|---|---|
| Photos | never stored by us (processed and discarded) |
| Transcribed scan text | 7 days |
| AI job records (problem, result, cost, errors) | 90 days |
| Shared answer cache (no link to you) | until replaced or the cache version changes |
| Account, credits, ad records, Google sign-in link | until you delete your data |
| Purchase records | as tax and accounting law requires, unlinked from you after deletion |
| Device counters (fraud prevention) | up to 400 days, unlinked from you after deletion |
| Crash reports | 90 days |
| Usage analytics | 14 months |
| Age range you told us | on your phone until you delete your data |
| Synced history (Google sign-in with Sync history on) | until you delete the item or delete your data |
| In-app feedback (and an attached problem, photo or e-mail) | 180 days, then deleted automatically |
| On your phone (history, settings) | until you delete them or the app |
9. Deleting your data and your rights
- In the app: Settings → Privacy → Delete my data deletes your history on the phone, your synced history, your credits, your account and its Google sign-in link, the feedback you sent from the app, the age range you told us (the app asks again), and the server records linked to you, and it resets usage analytics. It does not cancel a Plus subscription: cancel it in Google Play.
- On the web: https://solved-math.halfpast.io/delete-account.html (with Google sign-in, or with the Support ID for accounts without it).
- By e-mail: privacy@halfpast.io.
Depending on where you live, you may also have the rights to access, correct, delete, restrict, object to and port your data, to withdraw consent at any time, and to complain to a regulator. We answer within one month (EEA/UK) or 45 days (US states). We do not discriminate against you for using your rights.
10. Regional information
10.1 EEA, UK and Switzerland
- Controller: Sergiy Bondarev, IČO 23604280. We are established in the EU (Czech Republic), so no EU representative is needed, and we have not appointed a data protection officer because the law does not require one for our processing.
- Legal bases: as in §3: contract for the service you ask for; legitimate interest for security, fraud prevention (you may object); consent for crash reports, usage analytics and personalised ads; legal obligation for accounting.
- Digital-consent age: we do not rely on consent from anyone who may be under their country's digital-consent age (13–16 depending on the country).
- Ads: limited ads for users who may be under 18; for users 18 and over, personalised ads only with consent (§5). Complaints: your national data protection authority (in the UK, the ICO).
- UK Children's Code: high-privacy defaults, no profiling, no nudges to weaken privacy, and this plain-language summary.
10.2 United States
- Categories collected (CCPA/CPRA terms): identifiers (anonymous account id, device ids, advertising ID via AdMob), commercial information (purchases), internet or electronic activity (problems you send, ad views, which app features you use). Inferences: none. Sensitive personal information: none.
- No sale. We do not sell personal information, and we do not share data of users who may be under 18 for cross-context behavioural advertising. For users 18 and over, ads may be personalised by Google (§5).
- Your rights: to know, access, delete, correct, to opt out of targeted advertising and sharing (turn off Settings → Privacy → Usage analytics, and delete or reset your advertising ID in your phone's settings), and to appeal a refusal by writing to privacy@halfpast.io.
- COPPA: we comply with the Children's Online Privacy Protection Act and do not knowingly collect personal information from children under 13 (§1).
- App-store age signals: where a state law makes the store give us an age range, we use it only to provide an age-appropriate experience and to comply with the law.
10.3 Brazil
Solved Math is not offered in Brazil yet. When it is, this section will describe processing under the LGPD and the Statute of Children and Adolescents (ECA and Digital ECA).
11. Security
Data is encrypted in transit (TLS) and at rest by Google Cloud. Only the app's servers can read account data; there is no direct client access to the database, except your own synced history, which only you can read and change when signed in with Google (enforced by the database's security rules). AI provider keys live only on the server. Photos are downscaled and stripped of location data on your phone before they are sent.
12. Changes
We will update this policy when the app changes and tell you in the app about important changes before they take effect.
13. Contact
Sergiy Bondarev, IČO 23604280, Bachmačská 691, 280 02 Kolín, Czechia. privacy@halfpast.io (privacy questions, parents and guardians, deletion). See also our Terms of Service.