Master is an app for independent tradespeople and small service teams: clients, sites, estimates, jobs, documents and payments. The app works on the device and does not send your work records to the developer.
This is a translation for convenience. If the texts differ, the Russian version prevails.
Who is responsible for the data
Master is developed by Korseon Labs. The person responsible for data processing is Sergei Koroshev, self-employed, Russian taxpayer ID (INN) 772422836834. Contact for data and support questions: support@korseonlabs.ru.
You enter and use information about your clients yourself, for your own work. The developer has no access to it: it is stored only on your device and in files that you save or send yourself.
Data stored by the app
- Client names, phone numbers, messengers, email addresses and notes.
- Site names and addresses, with comments.
- Estimates and their lines, jobs, work dates, statuses and payment records.
- Job photos that you take or select.
- Your document profile: name or company, phone, email, business details, note, logo and signature image.
- Your price list of labour and materials, chosen trade, reminder settings and a technical log of delivered notifications.
You decide what to enter. No registration or account is required.
Where the data is stored
All records, settings and copies of images are kept in the app's private storage on the device. The app has no internet permission: it does not send data to servers and does not use advertising, behavioural analytics or third-party data-collection SDKs.
Android automatic backup and device-to-device transfer are disabled. The app database is not separately encrypted, so its protection depends on your screen lock and device security.
Calls, messages and maps
The Call, SMS, WhatsApp, Telegram and Map buttons work only when you tap them. They open the chosen app and pass it the client's phone number or the site address. Further processing is governed by the rules of the opened app. Master does not read your messages, call log or contacts.
Photos and documents
The camera and image picker open only on your action, through Android system components. The app gets access only to the selected picture, not to your whole gallery. The picture is copied to private storage; the original in your gallery stays untouched.
PDF estimates are created on the device. When sharing, you choose the app and the recipient in the Android share menu. Temporary files for sharing are kept in the app cache and removed automatically. The signature image is inserted into the PDF as a picture and is not an electronic signature.
Backups
You create backups manually and save them to a location of your choice, including a cloud service. A backup is protected by your password (AES-256-GCM, key derived with PBKDF2). The password is not stored by the app and is not sent to the developer: without it the backup cannot be restored. If you keep a backup in a cloud service, its storage is governed by that service's rules.
Notifications and permissions
Reminders about jobs, payments and estimates are created on the device. On Android 13 and later, the notification permission is requested when you turn reminders on; declining does not affect clients, estimates or jobs. A notification may contain a job title — keep this in mind for lock-screen notification settings.
Technical permissions are used by the Android scheduler (WorkManager) so that reminders survive a reboot. The app does not request access to contacts, location, microphone or device storage.
Retention and deletion
Data is kept until you delete it. In the app you can delete a payment, job, estimate, site and client. To delete everything at once, clear Master's storage in Android settings or uninstall the app. Without a saved backup the data cannot be restored.
Saved PDFs, backups and files sent to clients are outside the app. Delete them separately where they are stored.
Support requests
If you write to the developer, the developer receives only what you included in your message and uses it to reply. Do not send backup passwords and, unless necessary, your clients' contacts and addresses. Send requests to delete correspondence to support@korseonlabs.ru.
Changes to this policy
If the set of data changes or new services are added, such as cloud sync or purchases, this policy will be updated before such a version is released. The current text is available in the app under More → Settings → Privacy and at https://korseonlabs.ru/apps/master/privacy.