Third-party notices
HeatSeeker includes or is built with this open-source software, each used under its own license.
ExtPay.js 3.1.2 (ExtensionPay client)
By Glench, github.com/Glench/ExtPay. Used in the Chrome extension only; the free desktop and phone apps don't include it. License: the project's LICENSE file is the GNU LGPL v3.0 (which builds on the GNU GPL v3.0); its package.json says GNU AGPL v3.0 or later. HeatSeeker meets the terms of either. The extension ships a modified copy: its webextension-polyfill import is replaced by Chrome's own chrome API. That source ships readable inside the extension (src/vendor/ExtPay.js), with the license texts, and is available on request under the same license.
Electron
Desktop app. MIT License, license text.
Capacitor
Phone apps. MIT License, license text.
cordova-plugin-inappbrowser
Phone apps. Apache License 2.0, license text.
@capacitor-community/admob
Phone apps (ads in the free edition). MIT License, license text.
The desktop app's other npm packages are under permissive licenses (MIT, ISC, BSD, Apache-2.0); their notices are kept inside the installed app.