How to collect and consolidate application health across instances in aws

We deploy several applications across EC2 instances. They are jar files, war files on Tomcat, npm based UI applications and python scripts.

Each has a different way of validation. For war files under Tomcat webapps I can check the swagger UI. For UI projects I can check the application link. For standalone jar and python scripts I check the process, if running.

Is there a way I can place checks(on the vm or in AWS) that send status(up/running or down/offline) to AWS so it is viewable for all applications across all instances?

I thought about using monit i.e. write config to monitor processes and links of individual applications. But there is no way to send it to a "one place" dashboard in AWS Monit has it's own dashboard but it is instance specific. So if I have 20 instances there's 20 dashboards like http://IP:2812/. It has a centralized dashboard offering which is not open source so I cannot use it

I checked the AWS resource health sub category within Cloudwatch. That is limited to cpu/memory/status checks and I don't see a way for customization to track individual jar/war files

I checked AWS X ray, and seeing that it requires changes to the application code makes me think it will extract too much data like number of 4XX and 5XX(which isn't the need since all I need to do is check links or processes and report it visually)

Is there a way to visualize resource health of all applications on all instances on a single dashboard/page either in AWS or some opensource tool?

I suggest you monitor the application rather than the infrastructure. Cloudwatch Synthetics acts like a web browser and can alert based on the results of the request.

If you want to monitor at the component level you will have to write some kind of script that sends data to CloudWatch Metrics or Cloudwatch Logs using the API, which isn't particularly difficult. From there you can alert on metrics, or use metric filters to alert on log contents.