Protagoras Classics Lexica is an iPhone app developed by Adrian Packel that provides fast and convenient access to six essential classics reference works. Included with the app at no cost are the renowned lexica by Liddell-Scott-Jones and Lewis and Short, as well as their intermediate and elementary versions. Additionally, the app offers Autenrieth's Homeric Dictionary and Slater's Lexicon to Pindar, two specialized works.

With Protagoras, users can effortlessly browse any of the dictionaries by section or search for entries directly. Greek entries can be searched using the built-in Greek keyboard, Latin transliteration, or standard Beta Code. When viewing an entry, the app automatically displays cross-referenced entries, although this feature is still being perfected.

One of the standout features of Protagoras is the ability to view the text of cited passages on the Perseus Digital Library. This integration allows users to explore the original sources and deepen their understanding of the referenced texts.

Furthermore, the app enables users to search any dictionary for words that include a specific English term in their definition. This powerful search capability makes it easier to find relevant entries and expand one's knowledge in classical studies.

Protagoras also offers convenient bookmarking functionality, allowing users to save frequently accessed entries for quick reference. The history feature enables users to easily navigate back to recently viewed entries, enhancing the overall user experience.

Overall, Protagoras Classics Lexica is a comprehensive reference app that provides classical scholars, students, and enthusiasts with a wealth of valuable resources. Its user-friendly interface, powerful search capabilities, and integration with the Perseus Digital Library make it an indispensable tool for anyone studying or researching the classics.