Anything specific?
Get your contacts in Israel to use Whatsapp, Viber, or Skype -- so you can use those VoIP apps to call for free.
If you have workers in Israel, get them SIP phones or SIP clients on their phones/computers and connect them to an Asterisk server. (You can spin off an asterisk server on the cloud for $5/month) , and then each SIP client will become an extension you can dial.