As I've been writing Ignition Module code, I've found it useful to have a clean project to run some simple tests on so I can throw in code without affecting any of my live modules.
Here's my Playground project. Tested and running against Ignition 7.2, 7.3, 7.4, and 7.5 Module SDK.
I plan to keep this post updated as new versions are released.
Download it here: IgnitionModulePlaygroundv75.zip
1) Make sure you have the Module SDK.
2) Extract the files in the zip into your module workspace. (Default is "Module SDK 7.3.1\example". I copied that directory from the SDK to "C:\Development\Module SDK 7.3.1 Workspace\" on my system.)
3) Make sure the build-playground.xml and the module-playground.xml end up in the Build folder, alongside the Module SDK's build.xml.
4) In Eclipse, refresh your Build project, and import the three new projects. (Right click in the Package Explorer, go to "Import...", select General -> Existing Projects into Workspace, browse for the root directory, and click Finish.)
5) Note: From time to time, the requiredframeworkversion in the module.xml files need to be changed as new versions are released. Make sure your requiredframeworkverison matches that in the ModuleSDK's example module xml files. I try to keep the version in this download updated, so you may have to decrease the version number if you're using an old version of Ignition.
Ignition Version: 7.2, 7.3, 7.4, 7.5