NetBeans 8 is not provided in a downloadable configuration that is explicitly available for the mobile application developer. The nearest preconfigured download is the All bundle, which includes all of the NetBeans tools ranging from those for the mobile developer to all of the tools required for an enterprise developer. Clearly, there's a need for the mobile developer to be able to install only the plugins they require without the need for additional unnecessary plugins.
Fortunately, it's a straightforward task to add mobile development support to the smallest NetBeans distribution—the Java SE download, as shown in this recipe.
To complete this recipe, you need to have downloaded and installed either the Java SE or Java EE download bundles of NetBeans.