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Attributions

Attributions

Version 1 · Updated 17 October 2026

Quiztador is built with the help of other people's work. This page credits the open-source software, fonts, sounds and pictures we use, and contains the notices their licences ask us to show. Thank you to everyone who made them.

Question pictures

Many question pictures come from these free image services. We only use pictures that may be used freely without credit, but we want to thank the photographers and the services anyway:

Did you take a picture used in Quiztador and want it credited or removed? Email info@quiztador.com.

Fonts

  • Jost – Copyright 2020 The Jost Project Authors (https://github.com/indestructible-type). Licensed under the SIL Open Font License 1.1.

  • Yellowtail – Copyright (c) 2011 by Brian J. Bonislawsky DBA Astigmatic (AOETI). Licensed under the Apache License 2.0.

  • Roboto – Copyright 2011 Google Inc. Licensed under the Apache License 2.0. Roboto is a trademark of Google.

  • Ionicons – Copyright (c) 2015-present Ionic. MIT License.

  • Font Awesome 4.7 by Dave Gandy – font licensed under the SIL Open Font License 1.1.

  • Lucide icons (website) – Copyright (c) Lucide Icons and Contributors. ISC License.

Sounds

  • Sound effects by Kenney (kenney.nl), released under CC0.

  • [OTHER SOUNDS AND MUSIC – SOURCE TO BE CONFIRMED]

Services and SDKs

The app includes these services' software, which is used under their own terms:

  • Firebase (Analytics, Authentication, Cloud Firestore, Cloud Functions, Cloud Messaging, Cloud Storage, Crashlytics, Performance Monitoring, App Check) and Google Sign-In by Google LLC – Firebase terms. Several of the Firebase SDKs are open source under the Apache License 2.0.

  • Unity LevelPlay (ironSource and Unity Ads) – Copyright © ironSource Ltd., a Unity company. Used under the Unity Advertising Terms of Service.

Open-source software

The Quiztador app and website use the following open-source software. Each is copyright of its authors and is used under the licence shown; the licence texts are at the end of this page.

MIT License

  • React and React Native – Copyright (c) Meta Platforms, Inc. and affiliates

  • Expo and its modules (expo-apple-authentication, expo-application, expo-asset, expo-audio, expo-blur, expo-build-properties, expo-clipboard, expo-crypto, expo-file-system, expo-font, expo-haptics, expo-image, expo-linear-gradient, expo-notifications, expo-splash-screen, expo-store-review, expo-tracking-transparency, expo-updates, expo-video) – Copyright (c) 650 Industries, Inc. (aka Expo)

  • @expo/vector-icons – Copyright (c) 2015 Joel Arvidsson, Copyright (c) 2020 650 Industries

  • React Navigation – Copyright (c) 2017 React Navigation Contributors

  • react-native-reanimated, react-native-gesture-handler, react-native-screens, react-native-worklets – Copyright (c) Software Mansion

  • react-native-svg – Copyright (c) 2015-2016 Horcrux

  • react-native-safe-area-context – Copyright (c) 2019 Th3rd Wave

  • react-native-pager-view – Copyright (c) 2021 Callstack

  • react-native-webview, @react-native-community/netinfo, @react-native-masked-view/masked-view – Copyright (c) Facebook, Inc.

  • @react-native-async-storage/async-storage – Copyright (c) 2015-present Facebook, Inc.

  • react-native-gifted-chat – Copyright (c) 2019 Farid from Safi

  • react-native-iap – Copyright (c) 2025 hyochan

  • react-native-keyboard-controller – Copyright (c) 2021 Kiryl Ziusko

  • react-native-nitro-modules – Copyright (c) Marc Rousavy

  • react-native-nitro-google-signin – Copyright (c) 2026 react-native-nitro-google-sign-in

  • react-native-otp-entry – Copyright (c) 2023 Anday

  • react-native-qrcode-svg – Copyright (c) 2016 JerryShen

  • react-native-reanimated-carousel – Copyright (c) 2020 Doho

  • react-native-email-link – Copyright (c) 2019-2024 Includable

  • UI Kitten and Eva Design System – Copyright (c) akveo

  • react-hook-form and @hookform/resolvers – Copyright (c) Beier (Bill) Luo

  • zod – Copyright (c) 2025 Colin McDonnell

  • dayjs – Copyright (c) 2018-present iamkun

  • lodash – Copyright OpenJS Foundation and other contributors

  • Next.js and Vercel Analytics – Copyright (c) Vercel, Inc.

  • TanStack Query – Copyright (c) 2021-present Tanner Linsley

  • Radix UI – Copyright (c) WorkOS

  • shadcn/ui – Copyright (c) shadcn

  • cmdk and next-themes – Copyright (c) Paco Coursey

  • sonner – Copyright (c) Emil Kowalski

  • input-otp – Copyright (c) Guilherme Rodz

  • next-share – Copyright (c) Bunlong

  • react-cookie – Copyright (c) Benoit Tremblay

  • recharts – Copyright (c) recharts group

  • tw-animate-css – Copyright (c) Wombosvideo

  • SDWebImage – Copyright (c) 2009 Olivier Poitrey; SDWebImageAVIFCoder and SDWebImageSVGCoder – Copyright (c) lizhuoli1126; SDWebImageWebPCoder – Copyright (c) Bogdan Poplauschi

  • Reachability.swift – Copyright (c) Ashley Mills

  • SwiftUI Introspect – Copyright (c) Timber Software

  • Hermes – Copyright (c) Meta Platforms, Inc. and affiliates

  • {fmt} – Copyright (c) Victor Zverovich

Apache License 2.0

  • React Native Firebase – Copyright (c) 2016-present Invertase Limited & Contributors

  • Firebase SDKs, GoogleUtilities, GoogleDataTransport, Google Sign-In, GTMAppAuth, GTMSessionFetcher, AppAuth, AppCheckCore, Promises – Copyright Google LLC and contributors

  • Abseil, gRPC – Copyright The Abseil Authors, Copyright The gRPC Authors

  • Folly – Copyright (c) Meta Platforms, Inc. and affiliates

  • fast_float – Copyright (c) The fast_float authors

  • class-variance-authority – Copyright (c) 2022 Joe Bell

BSD Licenses

  • LevelDB – Copyright (c) 2011 The LevelDB Authors

  • libwebp – Copyright (c) 2010, Google Inc.

  • libavif – Copyright (c) 2019 Joe Drago

  • dav1d – Copyright (c) VideoLAN and dav1d authors

  • glog – Copyright (c) 2008, Google Inc.

  • double-conversion – Copyright 2006-2011, the V8 project authors

  • SocketRocket – Copyright (c) Facebook, Inc.

Other licences

  • BoringSSL – ISC License and OpenSSL License

  • nanopb – Copyright (c) 2011 Petteri Aimonen. zlib License

  • Boost – Boost Software License 1.0

  • Lucide – ISC License

Trademarks

Apple, the Apple logo, Sign in with Apple and App Store are trademarks of Apple Inc. Google, Google Play, the Google Play logo, the Google "G" logo and Roboto are trademarks of Google LLC. Unity and ironSource are trademarks of Unity Technologies. Other names may be trademarks of their owners.

Licence texts

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

BSD 3-Clause License

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

  3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

ISC License

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

zlib License

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution.

Apache License 2.0, SIL Open Font License 1.1 and Boost Software License 1.0

The full texts are available at apache.org/licenses/LICENSE-2.0, openfontlicense.org and boost.org/LICENSE_1_0.txt. Software under the Apache License is distributed on an "AS IS" basis, without warranties or conditions of any kind.