It was a time while we write every single lines in CSS and try to make fit in all the devices before. And its very hard to get what our clients expected from us. But now a days its very fast and easy to do with styling frameworks such as Bootstrap.
Bootstrap is developed by Twitter team and its getting popular day by day not by just advertise but by its easiness to use and understand the overall framework. Its documents are awesome super easy to understand and apply. 40% of work has been reduced by Bootstrap for front end designers. Everyone loves it because its fit on whatever device you open.
Evey bootstrap set will comes with those inbuilt components even it integrate ready with glyphicons even that plugin works well but applying those elements in design pages are not so difficult it can be used by any baby step designer. Adding the external plugins like fontawesome makes it more elegant and beautiful.
Hopefully it will rise and popular more than we think in next couple of years. We want thank you to all the bootstrap developer team for providing such awesome front end framework to reduce the daily hassle to all the developers.