Your Moodle should be available on all devises with access to the Internet via a browser. You might want to use a theme for mobiles though. From Moodle v. 2 go to Settings - Appearance - Themes - Theme selector. Then choose Change theme for Mobile. In a standard Moodle installation there is a theme called MyMobile you can use.
There is an app available for Moodle, but it don't work for us and it will not be updated. Moodle has stopped supporting it, see Martins posting "Mobile Moodle app moving to HTML5" in the Recent news forum
I can not help you with flash on apple devices, they do not support flash.