Rehearsal Assistant is an open source voice/audio recorder. You may organize recordings, record reminders and lists, and annotate events. Though this app is still actively available, it doesn't appear to be regularly updated or offer fixes to current bugs.
GoodReader is a PDF reader for iPad, iPhone and iPod Touch. GoodReader allows you to read anything -- books, movies, maps and images -- on your mobile device.
HearPlanet is a real-time audio tour guide. This application plays audio tracks based on points of interest surrounding your current location; it pulls from Wikipedia as well as user-created content and other partners. Compatible with iPhone, iPod Touch, and Android OS.
Nature.com reader apps allow you to read scientific content on the iPhone, iPad, iPod Touch, or Android. You may browse news and free open access content, save material to read for later, save searches, and access the articles' references. With a subscription you will have full access to their content.
Noter is a to-do list application for the iPhone, iPad, or iPod Touch. You may open up Noter on your iPhone or sync with your computer.
QuickVoice iP is a voice recorder for Mac and Windows, as well as the iPhone, iPad, and iPod. You can record voice notes, reminders, dictations, meetings, to do lists and entire lectures.
Bibliogo is a journal article web app that allows you to create and share bibliographies, manage journal alerts, follow feeds, tag citations, and order articles. You can connect your LinkedIn account, and others, with this web-based app.
Google Alerts are email updates of the latest relevant Google results (web, news, etc.) based on your queries.
Google Scholar Citations lets you track citations to your publications, check who is citing your publications, graph your citations over time, compute citation metrics, and view publications by colleagues.