iPhone/iPad: The native PDF reader on portable Apple devices isn't quite a genius app, especially with larger files. To read huge PDFs, Office docs and other documents, and grab them over Wi-Fi, Dropbox or other web services, try GoodReader.
GoodReader Lite, the free version for iPhones and iPod touch models, has been declared by raters as very reliable when it comes to reading large documents that the iPhone native app often crashes out on. You can transfer files to GoodReader over a Wi-Fi network, grab them from a WebDAV-compatible server, and with cheap add-ons, grab files natively from Dropbox, Google Docs and other services. The document navigation is fairly smooth, the control offerings helpful, and GoodReader Lite just works.
GoodReader, the full $1.19 version, includes native design for iPads and does a few other tricks that the Lite version doesn't quite cover. Either way, GoodReader seems like a nice alternative for those who want to read PDF-based ebooks and other texts on their iPhone or iPad and don't quite need to convert them to ePub ebooks.
GoodReader and GoodReader Lite are available for iPhones, iPod touch and iPad devices, free and $1.19, respectively.