could you please clarify?
Do you intend to monitor an Azure Web App with a SaaS-based application, or do you want to know whether it's possible to monitor an app deployed to Azure Web Apps (in which case, it would be PaaS instead of SaaS).
Anyway, I can answer both questions 🙂
Dynatrace is a SaaS-based monitoring tool that also allows monitoring of Azure Web Sites (ie deployed to PaaS).
AppMon will be able in v7 to monitor apps deployed to Azure Web Sites.
Hope that helps