I don't see any ReadItLater related topics on StackApps, our site for applications that interact with Stack Exchange.
As Ivo mentioned, using favourites is easy. Simply navigate to your profile and hit Favourites. Stack Exchange mobile even supports you favouriting, and will load perfectly. I frequent it using an iPod Touch. You can look over on this page to see which browsers are officially supported by Stack Exchange - there is no guarantee your mobile browser will function.