You can call another application in the iOS environment by creating a URL request with a specific scheme. therefore, to open an email or phone application, in your html,
<a href="tel:+919900600233" class="call mobile"></a>
<a href="mailto:help@domain.com" class="email"></a>
When the user intercepts this hyperlink, the user will be sent to the appropriate applications. just like a messaging app use
<a href="sms:+919900600233" class="SMS"></a>
List of All URL Schemas : iOS URL Schemas
source
share