iOS 11 GUI — Now available for Figma!
iOS 11 GUI — Now available for Figma! is a free UI Kit design resource made by Dribbble user Yuri Yasyuk. As far as I can tell, its license is Custom License.
Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.