That's strange. I just went into my eBay Dev account to check on this. The URL for the old tool was:
https://developer.ebay.com/DevZone/build-test/test-tool/ ...which redirected to this API tool info page:
https://go.developer.ebay.com/api-test-tools ...and on that page I see "Note: The previous eBay API Test Tool is no longer supported." (sigh)... I guess they're retiring that tool, for some reason. It's a pity, as it was pretty handy. Looks like there are 3P tools around, but I don't really feel like giving them my API keys or tokens.
Thanks for the clarification, Andreas. I was commenting in general about my hesitation regarding the security of 3P tools. But then I re-found and had a closer look at your API Playground, and it looks like you guys are pretty sensitive to security and addressing the handling of said data well. Next time I need to fiddle with the Trading API, I'll be visiting your site/tool to give it a whirl. (I think eBay should link to your tool from that above "API Test Tools" page.)
@davidtsadler, the tutorial is very clear. I have already tested it but I did'nt pay enough attention to the details, so I gave up. By reading the tutorial I realize I've made some mistakes, I'll try it again. Thanks.