I released Amon 3.0 two months ago and the response and the feedback I got since then was overwhelming. Based on that feedback I've been hard at work and managed to release 3 major updates. Amon 3.1 came with support for Collectd metrics. In Amon 3.2 I introduced application metrics. Amon 3.3 was extension oriented - it came with an API, so you can install your agents with devops tools like Ansible and Puppet and also Webhooks - for implementing sophisticated alerting systems like VictorOps and PagerDuty.
Which brings us to today and a release I am really proud of - Amon 3.4. With 3.4 I tried to solve a problem prevalent in both the open source and hosted monitoring tools out there and that is - detailed performance data when it comes to databases and web servers. As an example - in most tools you are able to see general throughput information like Inserts/Updates/Deletes per second or Requests per second for the web servers, but you still don't know what is actually going on. To investigate - you have to login in your database, execute performance queries until you find the culprit. It is even worse for web servers - in both Apache and Nginx all that information is log files which are difficult to analyze without additional tools.
Starting with Amon 3.4 all that information is collected by default - slow queries, index and tables sizes, index hit rate. For Nginx and Apache - it collects performance information about every individual requests. You can check all the plugins live, at the demo site and below you can see the full list with metrics that are available right now, with more coming in the future.
I've created a detailed Roadmap for what is coming in the next couple of months. Right now I am focused on the 2 most requested features: Windows Support and syncing Amazon Cloud Watch Metrics(EC2, RDS, etc), but priorities could change based on your feedback. Above everything else - Amon is a 100% feedback driven product, so please let me know what you like and dislike about it and what features you want to see sooner.
I am always happy to talk and help.