This is a great list of ways to curate content. Most of them also have apps. Diigo and PearlTrees work well on iPad. Flipboard is another great option.
With Pocket, it's possible to curate content to read offline or online. It has similar features as Diigo, but uses a visual interface similar to Flipboard. Definite potential here.
"The debate over digital learning will soon enter a new phase. No longer will educators debate whether or not digital learning has the capacity to transform the American education system. Just about gone are the anti-technology Luddites who insist that every classroom be self-contained, with students and teachers left to their own devices, save for the help of pencils, chalk, blackboards and weighty textbooks stuffed into 10 kilo backpacks." - from ISTE about the need for the new Mobile Learning Group.