AppSignal is a platform that provides performance monitoring and error-tracking tools for applications and websites. It offers solutions for developers to monitor the performance of their applications in real-time, track errors, and diagnose issues. The platform provides insights into application performance metrics such as response time, throughput, and error rates. It also offers features for tracking and managing errors, including alerting developers of critical issues and providing detailed error reports for debugging purposes. Additionally, AppSignal offers integrations with popular programming languages, frameworks, and tools.