"iSSRN, our free iPhone App, was released recently. It provides instant access to the latest Social Science and Humanities research in the SSRN eLibrary from scholars around the world. iSSRN is available from Apple's iTunes store.
iSSRN allows iPhone and iPod Touch users to search over 250,000 papers and read the full text of the papers directly on their device. Note: This is an updated version of the previous iSSRN App and this version, not the previous one, will be updated in the future." - SSRN Blog