After its initial funding from pan-European seed fund and incubator Seedcamp, Server Density, the server monitoring tool, has secured £135k in an Angel round from Christoph Janz, Qamar Aziz, Kyle McGinn and Distilled.net.

The new investment will be used to accelerate growth through “several new projects.” To that end, the UK startup is also announcing its new “app store for sysadmins” at today’s MongoDB conference in San Francisco.

Essentially it’s a plugin marketplace for customers of Server Density’s server monitoring service enabling developers to sell (or give away) their plugins that extend and add specialist features to the functionality of the company’s core product.

Like similar monitoring services, Server Density makes it easy for system admins to monitor the performance of servers, get alerted to issues before they (hopefully) become an issue and receive status updates. Along with its browser-based version, the company offers mobile versions via dedicated apps for iPhone, iPad and Android.

Founded by David Mytton, Server Density’s customers include companies such as Intel, Motorola, University of Oxford, Duckduckgo, about.me and The New York Times.