The original thing isn't playable anymore sadly, a few years ago, the app on the iphone was the best we could get, and even the webinterface was quite doable, as long as you sticked to the older version of cookieclicker.
Thanks for the suggestion about megacookies and their upgrades, i will give it a good thinkthrough and perhaps i will have a version 1.1 ready by christmas this year, which will hopefully diminish the boarders it has now. But, i have to think on how to convert them back to previous versions, for example, converting 0.1 megacookie back to 100.000.000 regular cookies. Of course, boarders should be put into place to prevent players to convert to many megacookies so the one billion limitation of bgt won't get in the way. I am toying with an option in the shop right now, or to create an kind of cookiebank on the main screen of the game. Of course, gigacookies can be converted back to megacookies
No promises, but it has my attention.