Modal Popup
Popup Maker™ – Best Rated
https://wordpress.org/plugins/popup-maker/
Easy Modal
https://wordpress.org/plugins/easy-modal/
Modal Popup
https://wordpress.org/plugins/modal-popup/
Modal Window – create popup modal window
https://wordpress.org/plugins/modal-window/
Popup builder
https://ja.wordpress.org/plugins/popup-builder/