What are the operating system requirements??

Hello.
Brand new here. Espionage looks pretty good but...what operating system is needed to use it? This seems to me to be a most obvious question, yet I've gone all over the home site page; support; about; then this forum and still can't find that out. Are the OS requirements a secret?
*Snow Leopard (OS 10.6.8)?
*Power PC or Intel only?
*Desktop machines, MacBooks, or mobile device App only?
Thanks
Brand new here. Espionage looks pretty good but...what operating system is needed to use it? This seems to me to be a most obvious question, yet I've gone all over the home site page; support; about; then this forum and still can't find that out. Are the OS requirements a secret?
*Snow Leopard (OS 10.6.8)?
*Power PC or Intel only?
*Desktop machines, MacBooks, or mobile device App only?
Thanks