Gess Technologies Ltd ("we", "us", "our" or "Gess Technologies") operates the Lumae application ("Lumae" or the "App").
This Privacy Policy explains what information Lumae handles, how it is used, who it may be shared with, and the choices available to you.
Lumae is designed to keep your personal library private. Lumae has:
Your Lumae library — including the books, quotes, notes, reading history and other information you enter — is stored on your own device.
If you choose to use iCloud sync as a Pro feature, your library is also stored in your own private iCloud database so that it can be synchronised across your devices. Gess Technologies Ltd does not have access to the contents of your private iCloud database.
Separately, and for everyone rather than only Pro subscribers, Lumae mirrors three small settings through your own iCloud account so they follow you between your devices. These are described in Section 4.
The main personal information that may reach Gess Technologies Ltd is limited to technical information associated with requests to our Google Books lookup service, principally your device's IP address. We explain this in more detail below.
Everything in your Lumae library is entered or created by you directly on your device. This may include:
Lumae does not transmit this library information to Gess Technologies Ltd. We do not operate a server that stores your Lumae library, reading history, notes, quotes or personal settings.
If you enable iCloud sync, your library is stored in your own private iCloud database and is synchronised by Apple's iCloud services. Gess Technologies Ltd does not have access to the contents of that database.
Lumae may request access to your camera when you choose to scan a book barcode or photograph a book cover.
When you scan a barcode, the camera feed is processed on your device to read the barcode.
Lumae does not send the camera image or video to Gess Technologies Ltd for barcode scanning, and the camera feed is not stored by Lumae for this purpose.
The barcode or ISBN obtained from the scan may then be used to search the book data services described in Section 3.
If you photograph a book cover, the resulting photo is stored locally on your device as part of that book's entry.
If you have enabled iCloud sync, that book information and associated cover photo may also be synchronised to your own private iCloud database.
The photograph is not sent to Gess Technologies Ltd.
Lumae uses Apple's standard photo picker to let you choose an existing photo as a book cover. The picker runs outside Lumae and returns only the image you select, so Lumae never requests access to your photo library and cannot see any other photo in it.
The selected image is stored on your device with that book and is not sent to Gess Technologies Ltd.
When you search for a book by title, author or barcode/ISBN, Lumae may contact third-party book data services to retrieve book metadata and cover images.
Lumae uses:
These services are used to help identify books and populate information such as titles, authors, ISBNs, publication information, descriptions and cover images.
Requests to Open Library and Apple's Books / iTunes Search API are made directly from your device.
Gess Technologies Ltd does not operate or intercept these requests and does not receive the search information sent directly to those services.
Those providers may process requests in accordance with their own privacy policies and terms.
Google requires an API key to access certain Google Books functionality. Because an API key included in a downloadable application could potentially be extracted, Lumae accesses Google Books through a lookup service operated by Gess Technologies Ltd at api.gesstechnologies.com.
When this happens:
Our lookup service receives only the information necessary to perform this lookup. It does not receive your name, email address, Lumae library, reading history or account information.
Lumae does not have user accounts, so we do not have an account identity that can be attached to these requests.
When you import a library from a CSV file, Lumae looks up missing book details using Open Library and Apple's Books / iTunes Search API only. Importing never sends requests to our Google Books lookup service, however many books the file contains.
Our lookup service does not log or permanently retain the search text or your IP address. Search text and IP addresses are not written to persistent storage as request logs.
We do maintain a temporary request counter to help prevent abuse of the service. For this purpose, an IP address is converted into a one-way salted hash. The original IP address is not stored, and the hash is automatically deleted when the relevant rate-limiting period expires, which is one hour.
The lookup service may store the book information returned by Google — such as titles, authors and cover images — so that the same book can be retrieved without making another request to Google.
This cached book information is not associated with the person who originally requested it, and is normally retained for no more than 30 days, or 7 days where no result was found.
The lookup service is hosted on a server located in the United Kingdom.
Where UK data protection law applies, we process the limited technical information received by our lookup service where necessary for the legitimate interests of operating, securing and preventing abuse of the service.
We do not use this information to create user profiles, analyse individual reading interests or deliver advertising.
Once a request reaches a third-party provider such as Google, Open Library or Apple, that provider's own privacy policy and terms govern its handling of the request. We do not control those providers' privacy practices.
If you subscribe to Lumae Pro and enable iCloud sync, your Lumae library is stored in your own private iCloud database and synchronised between your Apple devices signed into the relevant iCloud account.
Apple's CloudKit infrastructure provides account-based access controls and security for private iCloud databases. Your private database is associated with your iCloud account and is not visible to Gess Technologies Ltd through Apple's developer tools. Apple's own privacy and security policies apply to iCloud.
Gess Technologies Ltd does not have access to the contents of your private Lumae iCloud database and does not receive a copy of your library through iCloud.
Lumae Pro also offers automated backups to your own iCloud Drive, using a Lumae folder in the Files app. Those backups are stored in your iCloud Drive rather than on Gess Technologies Ltd's servers. We do not receive or retain a copy of those backup files.
Your use of iCloud is also subject to Apple's applicable terms and privacy policies.
So that changes made on one of your devices can appear promptly on another, Lumae registers with Apple's push notification service. This gives your device a push token, which is held by Apple. Gess Technologies Ltd does not receive the token and does not send push notifications: the only messages sent to it are silent signals from Apple's iCloud service telling Lumae that new changes are available to download. These signals never display anything on your screen. Lumae registers on every device, including where iCloud sync is not in use, in which case no such signals are sent.
Separately from the Pro sync feature described above, Lumae mirrors a short, fixed list of settings through Apple's iCloud key-value storage so that they follow you between your own devices. This applies to everyone using Lumae, is not a Pro feature, and is not affected by the iCloud sync setting.
The list is limited to:
These are stored in your own iCloud account, and Gess Technologies Ltd has no access to them. Your books, quotes, notes and reading history are not included, and neither are your theme, appearance or feature settings, which stay on the device they were set on.
Lumae can be used free of charge for a library of up to 25 books, and offers two auto-renewing annual subscriptions: Core and Pro.
Purchases and subscriptions are processed through Apple's App Store using Apple's StoreKit framework.
Gess Technologies Ltd does not receive your full payment card details, billing address or Apple Account password. Apple handles payment processing and subscription billing.
Lumae receives the information necessary to determine whether the relevant subscription is active and which features should be available to you. This information is used solely to provide and manage the subscription features within Lumae.
We do not use your subscription information for advertising or behavioural profiling.
If you use Lumae's Home Screen or Lock Screen widgets or the Reading Timer Live Activity, Lumae may place a small amount of information in a private, on-device storage area shared between the main App and its widget or Live Activity.
This may include information such as:
This information is used only to display the relevant widget or Live Activity. It remains on your device and is not sent to Gess Technologies Ltd.
If you subscribe to Pro and use the Lumae Apple Watch app, your iPhone sends the Watch a small amount of information about the book you are currently reading — its title, author and page progress — along with reading-timer state, so that the Watch can display and control the timer. This is exchanged directly between your own devices using Apple's Watch Connectivity framework and is not sent to Gess Technologies Ltd.
Lumae can remind you before a borrowed book is due back and, if you use ARC tracking, before a review of an advance reader copy is due. These reminders are local notifications: Lumae schedules them on your device, and they are not sent through, or seen by, Gess Technologies Ltd or any server we operate.
Lumae asks for your permission to show notifications the first time you save a loan end date or an ARC review deadline, not when you first open the App. You can withdraw permission at any time in your device's Settings, and each type of reminder can be switched off within Lumae.
A reminder shows the title of the book concerned and, for an advance reader copy, who sent it, together with the relevant date or reading progress. Depending on your notification settings, this may be visible on your Lock Screen or on other devices that display your notifications, such as an Apple Watch.
We do not:
Our Google Books lookup service stores book information returned by Google so that previously requested books can be retrieved more efficiently. That cached information is not stored together with the identity of the person who requested it.
Lumae allows you to export your entire library to a backup file at any time. A backup contains everything described in Section 1, including any charts you have saved.
You choose where to save or send that file, including through Apple's Files app, email, AirDrop or other options available through the iOS share sheet.
Once you export a file, you are responsible for where you store it and who you choose to share it with.
Gess Technologies Ltd does not receive a copy of manually exported backup files unless you independently choose to send one to us, for example as part of a support request.
Lumae also allows you to import and export your library using CSV files, including CSV files from services such as Goodreads.
CSV files are handled through Apple's standard file picker and share sheet. Gess Technologies Ltd does not receive a copy of files you import or export unless you independently choose to send one to us.
Exporting remains available to everyone, including users of Lumae Free, and after the Pro preview or a subscription has ended.
Because Lumae does not store your library on Gess Technologies Ltd's servers, you control the deletion of most of your Lumae data directly within the App.
You can edit or delete individual books, quotes and notes at any time.
Lumae also provides a Delete All Books option that permanently removes your local library and, where iCloud sync is enabled, the corresponding synchronised library data.
Uninstalling Lumae removes its local application data from your device, subject to Apple's normal handling of application and iCloud data.
If iCloud sync is enabled, data stored in your private iCloud database may remain in iCloud after you uninstall Lumae. You can manage or delete that data through Apple's iCloud settings and Lumae's available controls.
The settings described in Section 4 are likewise stored in your own iCloud account and can be removed through Apple's iCloud settings.
Our Google Books lookup service does not retain individual search requests or IP addresses in persistent request logs.
Temporary rate-limiting information is automatically deleted after one hour. Cached book information returned by Google is normally retained for no more than 30 days, or 7 days where no result was found, and may be removed or refreshed sooner.
Lumae is a general-purpose book-tracking application and is not specifically directed at children.
We do not knowingly collect personal information from children for the purpose of creating accounts, advertising, profiling or other targeted activity, because Lumae does not provide user accounts, advertising or behavioural profiling.
However, Lumae may be used by people of different ages. If children use Lumae, we aim to apply privacy protections appropriately and do not intentionally ask children to provide unnecessary personal information.
Because Lumae's core library data remains on the user's device or, where enabled, in the user's own iCloud account, Gess Technologies Ltd does not ordinarily receive that information.
If you believe that a child has provided personal information directly to Gess Technologies Ltd, please contact us using the details below.
Depending on where you live and which data protection laws apply to you, you may have rights relating to your personal information, including rights to:
Because Lumae does not store your library data on our servers, most actions concerning your library — including accessing, correcting, exporting or deleting it — can be carried out directly within Lumae.
If we hold personal information about you, such as information contained in a support enquiry, you can contact us using the details below to exercise any applicable rights.
If you are in the UK, you also have the right to complain to the Information Commissioner's Office (ICO).
If you are in the European Economic Area, you may also have the right to complain to your local data protection supervisory authority.
Your Lumae library is stored on your device or, if you enable iCloud sync, in your own Apple iCloud account.
Gess Technologies Ltd does not receive or transfer your library data internationally.
Our Google Books lookup service is hosted in the United Kingdom. Requests sent from that service to Google, and requests sent directly from your device to Open Library and Apple, may be processed in other countries by those providers.
Those providers operate under their own privacy policies and may use international infrastructure or transfers as described in their respective policies.
We take reasonable technical and organisational measures to protect personal information that we process.
Because Lumae is designed so that your library remains on your device or in your own iCloud account, Gess Technologies Ltd does not maintain a central database containing users' book libraries, reading histories, quotes or notes.
Our Google Books lookup service is designed to minimise the information it receives and does not retain individual search requests or IP addresses in persistent request logs.
No method of storing or transmitting information can be guaranteed to be completely secure, and we cannot guarantee the security of information processed by third-party services that we do not control.
Gess Technologies Ltd is the organisation responsible for the processing of personal information described in this Privacy Policy.
If you have a privacy question, want to exercise a privacy right, or believe that your personal information has been handled incorrectly, please contact us at:
Email: lumae@gesstechnologies.com
Gess Technologies Ltd Company number: 17350731 Registered in England and Wales
Registered office: 63 Edgwick Road, Coventry, CV6 5FP
We may update this Privacy Policy from time to time, for example if Lumae introduces a new feature, we change how a service operates, or applicable privacy law changes.
When we make changes, we will update the "Last updated" date at the top of this Privacy Policy.
Where appropriate, we may also provide an in-app notice of material changes.
We recommend checking this Privacy Policy periodically so that you remain aware of how Lumae handles information.
This Privacy Policy was last updated on 27 September 2026.