QMUL Mobile App: Amongst many other useful functions, the mobile app allows the user to search Library Discovery, and check their library accounts.
LibKey Nomad: Browser extension giving one click access to scholarly articles.
Many databases have apps, which allow the user to access material on tablets/iPads:
ACS Mobile Apps: American Chemical Society offers a range of mobile apps to broaden accessibility to their products.
NLM's Mobile Applications: United States National Library of Medicine offers a range of mobile apps for various resources. The database PubMed is part of this offering.
Google Scholar: Browser extension for Chrome.
There are also services, which are based around browser extensions. They can be useful discovering and accessing resources. For example:
Endnote Click: Browser extension which tries to make it easier for the user to search and download documents within their library's subscription, when not available, it tries to source it through Open access.
Open Access Button: Browser extension which enables users to search and download Open access articles.
Unpaywall: Browser extension, which enable the user to search and download Open access articles.
Altmetric Bookmarklet: Allows the user to access the latest Altmetric impact statistics for specific journal articles on their browsers.
Endnote: Endnote has both an IOS app and a bookmarklet. The IOS app allow the user to access their references and read their PDF on the go. The bookmarklet allows the user to easily grab references from websites.
Mendeley: Mendeley offers a web importer, which allow the user to easily grab references from online databases, such as Google Scholar and Web of Science.