In short
- Your XP, levels, streaks, statistics, history, badges, lesson progress and the display name you choose are stored only on your phone. We never receive them.
- There are no accounts and no cloud sync, and we run no server that stores personal data.
- Ask Wiz and the Arena opponents run entirely on your phone. Nothing you type to them is sent anywhere.
- The free version shows ads from Google AdMob, which uses your Android advertising ID. MathWiz Pro removes all ads.
- We do not sell, rent or trade personal information.
§1Who we are
MathWiz: Mental Maths Trainer (“MathWiz” or “the app”) is published by Epsilon Developers, an independent software publisher run by Satyam Kushwaha and Anurag Mahajan in India (“we”, “us”). This policy covers the MathWiz app for Android and this website, mathwiz.epsilondevelopers.xyz.
By installing or using MathWiz you acknowledge this policy. If you do not agree with it, please do not use the app.
§2What stays on your phone
MathWiz keeps what it needs in its private storage on your phone, which other apps cannot read. None of it is sent to us.
| Data | What it includes |
|---|---|
| Profile and progress | The display name you choose (it starts as “Learner”), XP, level, daily streak and the date of your last session |
| Practice history | For each session: score, accuracy, average answer time and mode. For each mode: attempts, correct answers and best scores. The hidden skill level of each section, which sets its difficulty |
| Achievements and learning | Badges you have unlocked and lessons you have explored |
| Settings | Theme, difficulty preference, sound, haptics, auto-check answers, notification choices, reduce motion, and whether Pro is active on this phone |
| Conversations | What you type to Ask Wiz or in Arena chat, and the replies, which are generated on your phone. Arena chat is kept only for the match you are playing |
§3What leaves your phone
MathWiz connects to the internet only for the purposes below. Each service is run by Google under Google’s Privacy Policy.
Advertising, in the free version
Google AdMob serves the banner, interstitial and rewarded ads in the free version. To show and measure ads and to prevent fraud, the Google Mobile Ads SDK collects your Android advertising ID, device and app information, an approximate location worked out from your IP address, and how you interact with ads. On Android versions that offer them, it may also use Android’s Privacy Sandbox advertising features (Topics and Attribution), which you can manage in Android Settings, under Privacy, then Ads. How Google uses information from apps that use its services.
MathWiz Pro subscribers see no ads, and the app requests none for them.
Your choice about personalised ads
Where the law requires it, including in the European Economic Area, the United Kingdom and Switzerland, the app shows Google’s consent form before any personalised ads. You can change your answer at any time in Settings, under Ad privacy options.
Purchases
Google Play Billing handles MathWiz Pro. We receive the subscription status, the plan you chose and a purchase token, so the app can confirm Pro. We never see your card number, billing address or bank details.
App updates
The app asks Google Play whether a newer version is available and, if you accept, Google Play installs it.
The typeface
The app’s typeface, Nunito, is downloaded from Google Fonts the first time it is needed and kept on your phone afterwards. Like any download, the request reaches Google with your IP address.
Things you choose to send
If you share a result or the app, Android’s share sheet sends what you choose to the app you pick. Links to this website, to Google Play or to your email app open in those apps, under their own policies.
Crash reports
MathWiz contains no analytics or crash-reporting SDK of its own. If you have agreed on your phone to share usage and diagnostics with Google, Google Play may give us anonymous crash and performance reports that do not identify you.
§4How the features use your information
- Practice, the Daily Challenge and the Brain Games. Problems are made on your phone, and your answers are saved to your local history to show your progress and tune the difficulty.
- Adaptive difficulty. Your accuracy and speed in each section adjust that section’s hidden skill level, on your phone.
- Arena Battle and Speed Sprint. Your opponents, their pace and their chat are generated on your phone. There is no matchmaking server and there are no other players.
- Ask Wiz. Wiz understands and answers what you type with rules that run on your phone. There is no AI model, no network call and no server.
- Notifications. Reminders are scheduled on your phone by the app itself, and put back after your phone restarts. No push server is involved.
- XP, levels, streaks and badges. Calculated and shown on your phone.
We do not build profiles of you, and we do not sell, rent or trade your information.
§5Permissions
| Permission | Why MathWiz asks for it |
|---|---|
| Internet and network state | To load ads in the free version, confirm purchases, check for updates, download the typeface, and tell whether you are online so the app knows which modes are available |
| Notifications | Optional reminders from Wiz. You can turn them off in the app’s Settings or in Android settings, and everything else keeps working |
| Run at start-up | To put your reminders back after your phone restarts |
| Vibration | Haptic feedback as you answer, when Haptics is on |
| Billing | To buy and restore MathWiz Pro through Google Play |
| Advertising ID and ad services | Used by Google’s ads SDK in the free version, as described in section 3 |
MathWiz does not ask for your location, camera, microphone, contacts, photos, files, phone or messages.
§6Children
MathWiz suits learners of all ages but is made for a general audience and is not directed at children under 13, or the minimum age where you live. It is not part of Google Play’s Designed for Families programme, because the free version shows ads and offers in-app purchases.
We do not knowingly collect personal information from children, and the app keeps its data on the phone. If a child uses MathWiz, we suggest a parent or guardian sets it up, manages the ad settings and considers Pro, which removes ads. If you believe a child’s information has reached us, for example in an email, write to us and we will delete it.
§7Keeping and deleting data
Your data stays on your phone until you remove it:
- In the app: Settings, then Reset progress, erases XP, streaks, badges and history at once.
- In Android: Settings, then Apps, MathWiz, Storage, then Clear data, removes everything the app stored.
- Uninstalling the app removes everything it stored.
Information handled by Google for ads, purchases, updates and fonts is kept under Google’s policies. The Data Deletion Notice explains how to manage it.
§8Your rights
Depending on where you live, including under the GDPR, the UK GDPR and India’s Digital Personal Data Protection Act, 2023, you may have the right to access, correct or delete your personal data, to restrict or object to its processing, to withdraw consent, and to complain to a data protection authority.
Because MathWiz keeps your data on your phone, you can see, change or delete it yourself at any time. For anything else, or for information we hold such as emails you send us, write to contact@epsilondevelopers.xyz.
§9Legal bases
Where data protection law applies, we rely on:
- Consent for personalised ads, through Google’s consent form, and for notifications.
- Contract to provide the app and any subscription you buy.
- Legitimate interests to show non-personalised ads that fund the free version, to check for updates and to keep the app secure, where these are not outweighed by your rights.
- Legal obligation where the law requires us to process or keep information.
You can withdraw consent at any time. Doing so does not affect processing that has already happened.
§10International transfers
Google may process the information described in section 3 in countries other than yours, including the United States, under the safeguards Google provides. We never transfer your app data anywhere, because we never receive it.
§11Security
Your progress is held in the app’s private storage, which Android keeps separate from other apps. Every connection the app makes uses HTTPS. No method of storage or transmission is perfectly secure, so please keep your phone itself protected.
§12This website
This website sets no cookies and loads nothing from third parties: its fonts and images are served from the site itself. It remembers whether you chose the light or dark theme in your browser’s local storage, which never leaves your browser.
The site is hosted on Vercel, which may log visitors’ IP addresses to deliver and secure the site, as its privacy policy describes.
§13Changes to this policy
When this policy changes, we update the date at the top of this page, and for significant changes we also tell you in the app. Continuing to use MathWiz after a change means you accept the updated policy.
§14Contact
Epsilon Developers, run by Satyam Kushwaha and Anurag Mahajan, India.
Email contact@epsilondevelopers.xyz. We aim to reply within seven working days.