JMX Custom Monitor for Web App To Send data to APM Insight

I'm using a monitor web app called Applications Manager Insight, this App can monitor the activity and parameters of an Web app installed in a Applications Server, the only problem is that i want to monitor a considerable number of apps and for each app i need to purchase a license. As option i think is possible to develop a custom monitor to send information as Troughput, Memory Use, time elapsed to complete some task... and other parameters. I'm new in JMX, anybody has some idea if that i want to do is possible?

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