AppDynamics is a full-stack application performance management and IT operations analytics that delivers problem resolution for highly distributed applications through transaction flow monitoring and deep diagnostics.
AppDynamics offers 15 days trial; no credit card is required.
New Relic is a SaaS-based web and mobile application performance management provider (APM). It allows monitoring and diagnostics for dedicated infrastructures, cloud, hybrid environments, and real-time tracking.
SigNoz is an open-source APM that helps developers monitor applications and troubleshoot problems in their deployed applications.