How can I download nRF8001-SDK?
You can download it here, under the "development tools and software tab".
Thanks for your answer, but I have not found a link there, only text.
Yes, that's true, on the nRF8001 page you have to click on the "development tools and software" tab. There you will find the downloads, among them is the SDK.
I clicked on your link "SDK", but that's what I see: "Code" - NRF8001-SDK (the black text, is not a blue link) "Name" - nRF8001 SDK Installer (the black text, is not a blue link) "Version" - picture of the "red lock". For examle, with nRFgo Studio I had no problems.
The red lock means that you have to register the product key that comes with your kit on your "My Page" on [url=https://www.nordicsemi.com/]nordicsemi.com[/url before you can download the SDK.