Well, it was fun while it lasted… It got approved at 18:19, and was withdrawn again at 20:22. I using the public API Credentials and that is not allowed.
I’ve requested an own Web API key, let hope they will provide it. The same page (Welcome to the Web API documentation 
- Homey Web API) also states
Does your company have a great idea for an app? Contact us to request a Web API key.
I may not be a company, but I do think it’s a great idea 
Edit: Get it while you can, don’t know how long the page will be alive: Timeline Manager App voor Homey | Homey
