International Telephone Input 
A jQuery plugin for entering and validating international telephone numbers. It adds a flag dropdown to any input, detects the user's country, displays a relevant placeholder and provides formatting/validation methods - Resmio version with updated relative path in css!
Based on the same plugin https://github.com/jackocnr/intl-tel-input
Contributing
See the contributing guide.
Links
- List of sites using intl-tel-input
- List of integrations with intl-tel-input
- Android native port: IntlPhoneInput