Please find QuickBlox UI Kit here - https://quickblox.com/ui-kit/ .
You can switch between different options of ready to use flows. The Kit is compatible with Sketch and cross-platform.
More information about Implementation you can get via this link - https://quickblox.com/ui-kit/ .
Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.