This JavaScript library gives an alternative of browser's default method's like alert, prompt, confirm and many more functionalities with Bootstrap theme.
Bootstrap3 Demo : https://jsmorpheus.flexinetsolutions.com/ghv/rashid2538/bootstrap-ui-components/bootstrap3-demo.html
Bootstrap4 Demo : https://jsmorpheus.flexinetsolutions.com/ghv/rashid2538/bootstrap-ui-components/bootstrap4-demo.html