Verto Phone & extension is a Chrome Application that can be used with FreeSWITCH mod_verto.
<extension name="screen_sharing">
<condition field="destination_number" expression="^(\d )-screen$">
<action application="set" data="effective_caller_id_number=${caller_id_number}-screen"/>
<action application="transfer" data="$1 XML default"/>
</condition>
</extension>