Indexes in ebooks can be ‘active’, with hyperlinks into the text. Should these links go to the page, paragraph, line or word level? This is a complex question, but the main concern may be the user interface in ebook reader applications. In this third article of a four-part series, Mary Coe and Jan Wright report on their investigation of how active ebook indexes are handled by applications on tablet devices. They conclude that ereader apps on tablet devices offer as much variation as browser-based reading apps and lack the consistency seen with dedicated ereader devices. (See the first article in this series in The Indexer 37(2), 125–40,for more on Web-based browser ereader applications, and the second article in The Indexer 38 (1), 29–44, for more on dedicated ereader devices.) Due to the variety of operating systems, devices, and app versions on tablets, there were also many variables that could affect the ability of users to navigate within ebooks on tablets, and in particular to access the index.