Yes, there's a demo for the AU/VST at https://klevgrand.se/products/tines/, to the left below the video, just next to the Buy button.
Being a sucker for electro-acoustic pianos of all kinds, I downloaded the demo. I have to say that I'm quite disappointed and will not buy it, even though it's so cheap. The sound is flat and has virtually no timbral evolution, no spectral envelope at all. There's no 'tine' character that I can hear, no sense of a hammer hitting a tine, just an anonymous initial click in the lower octaves. 'Tines' actually reminds me most of the ancient analog Roland EP-10 'piano' that I ill-advisedly bought some 40 years ago and soon got rid of.