Third-party licenses

Last updated July 12, 2026
PayAppCheck is proprietary software. No license to PayAppCheck itself is granted on this page. It is built with the open-source components below; we acknowledge their copyright and license notices here with thanks. Full license texts are available at spdx.org/licenses.

Fonts

Inter · © The Inter Project Authors · SIL Open Font License 1.1.
Material Symbols · © Google · Apache License 2.0.

Web application

React and React DOM · © Meta Platforms, Inc. and affiliates · MIT License.
React Native and React Native Web · © Meta Platforms, Inc. / © Nicolas Gallagher · MIT License.
Expo (expo-router and expo modules) · © 650 Industries, Inc. · MIT License.
react-native-svg, react-native-screens, react-native-reanimated, react-native-gesture-handler, react-native-safe-area-context · © Software Mansion and contributors · MIT License.
@microsoft/signalr · © Microsoft Corporation · MIT License.

Server

ASP.NET Core and Entity Framework Core · © Microsoft Corporation · MIT License.
ClosedXML (with DocumentFormat.OpenXml and ExcelNumberFormat) · MIT License.
SixLabors.Fonts · © Six Labors · Apache License 2.0.
PdfPig · © UglyToad · Apache License 2.0. Includes Adobe AFM font metrics under Adobe’s permissive license.
Npgsql and Npgsql.EntityFrameworkCore.PostgreSQL · PostgreSQL License.
Serilog · Apache License 2.0.
Google.Apis.Auth · © Google LLC · Apache License 2.0.
Swashbuckle.AspNetCore and Scalar.AspNetCore · MIT License.
PayAppCheck is software, not legal or tax advice. You review and confirm every number.
Billing and payment inquiries are handled by Paddle, our merchant of record.
AIA, G702, and G703 are marks of The American Institute of Architects. PayAppCheck is not affiliated with, endorsed by, or sponsored by AIA.