This extension allows to show testimonials on the frontend of your Magento 2 store, with either a slider or a grid mode. It can be also added as a widget, which has a lot of settings, like showing or hiding specific fields, do design changes and more. Also it is possible to enable form on the frontend, which will allow customers to add their reviews about website, which can later be shown on testimonials section.

For more information check out the blog article here https://www.yereone.com/testimonials-extension-for-magento-2/