This plugin can be used for for easy phone number input in international format with using flags of countries. Consist the option to set country automatically (using client IP) and phone number validation.
To start plugin work – you need to activate it and enable “Friendly int. phone field” on your “Phone” field. It’s really simple.

Also check WP WooCommerce version of the plugin here: Link

Features:

• Comfortable usability via admin panel
• Works with any WordPress theme
• Cross browser compatibility
• No coding required