Just add bootstrap-select-min.js and same css & add class .selectpicker
Select2 for custom search and select
Just add button class in  data-style like data-style="btn-primary btn-outline"
 add the following line  class="js-switch" data-color="#13dafe" to your input element. 
 You can add  data-size="small",data-size="large" to your input element for different sizes. 
 add the following line  class="js-switch" data-color="#13dafe" to your input element. 
 Bootstrap brand colors, use checkbox 
 Add simple checkbox-circle class 
use disabled in input tag for disable state
 With bootstrap colors, use radio class.
All buttons clickable
use disabled in input tag for disable state
Add data-role="tagsinput" to your input field & its automatically change it to a tags input.
You can also use select multiple to your input field.
You can also use group tag data-role="tagsinput" to your input field.
 Use the  data-plugin="touchSpin"  to create a Bootstrap style spinner.
 Use a select multiple as your input element.
 Use a select multiple as your input element.
 Use a select multiple as your input element.