ARM templates are a great tool when you want to automate provisioning of your environment. They're customizable, somehow flexible, easy to store and modify. What they lack - as many text tools - is a touch of abstraction. Most people are sightseers - that's why it's always a good thing to see what you're doing.
I'll paint this!
ARMVIZ is a free and OSS tool, which will visualize and help to validate your ARM template on a very high level. By saying "high level" I mean, that it helps to understand the structure of a template and basic dependencies rather than underlying relations when it comes to provision resources.
The very first visualization you'll see in ARMVIZ
Working with ARMVIZ
Currently there're two possibilities to work with ARMVIZ - either you open a template stored on your disk or write a new one inside the editor. The former helps to validate whether you have all components inside a template and all dependencies work well, the latter is actually a slightly better option when it comes to write JSON than Visual Studio(especially when VS goes mad while validating a JSON schema).
ARMVIZ suggests possible values but it won't limit them to the ones available for a field
When dependencies are removed from a VM, we can clearly see, that there're some problems with our template
In current shape ARMVIZ has very limited capabilities and can act only as a quick support when you have a very complicated ARM template. On the other hand, the possibility to write and see it increases your productivity and really helps when you're struggling to understand what is related to what and why.