iTurbo vs BiLibre DjVu and PDF Reader

This application performs a Direct Numerical Simulation (DNS) where the Navier-Stokes equations are solved for two dimensional incompressible homogeneous turbulence. These equations are a set of nonlinear partial differential equations. The time stepping is performed with a simple Euler method where the time step is calculated so that the CFL number does not exceeds the given number (should be less than 0.8 otherwise the simulation blows up). The equations are solved in the Fourier space where the calculation of the nonlinear term transforms to a simple multiplication. The main CPU usage is consumed by transforming the vorticity field back and fourth between the Normal space where the time-stepping is performed and the Fourier space where the nonlinear term is calculated.

The application for reading and cataloging books, textbooks, reference books and documents in DjVu and PDF formats in a modern, user-friendly style. Designed mainly for working with technical, scientific and educational literature. COMFORTABLE READING MODE • Crops a page margins in manual and automatic mode. • Themes, color schemes for reading (day, night, sepia and more). • Page turn with scroll, curl and slide. POWERFUL ANNOTATIONS • Notes, stickers and scraps. • Drawn annotations (Apple Pencil support and just by touching). • Exports annotations in HTML, PDF, RTF formats. • Synchronization of annotations and drawings in iCloud. • Unified view and management of all annotations in all the books at once. BUILT-IN THE SUMMARY EDITOR • Markdown formatting. • Exports summaries in HTML, PDF, RTF formats. • Synchronization of summaries in iCloud. ADVANCED FEATURES FOR DJVU • Text recognition of pages in DjVu (for documents without OCR layer). • Splits a scanned double-page spread in DjVu into separate pages. WORKING WITH FRAGMENTS OF TEXT • Translation of separate words or complete sentences in different languages. • Full text searching in a book (textual, fuzzy and regular). • Built-in search for a selected text on the Internet, Wikipedia and Wolfram|Alpha. • Search for a word definition in a dictionary. • Text-to-speech in books. • Smart zoom by double-tap. CATALOGUER • Grouping by categories: by authors, subjects, sequences, publishers, tags, popular, recent, new, read and reading now. • Using tags to categorize documents. • Customizable search for books in the library by various metadata fields in different modes. • Search for textbooks on the Internet through arXiv.org, Library Genesis and Google. • Own folders tree and flexible bookshelf settings for layout and sorting. • Arranging books on a bookshelf by dragging. WORKING WITH A METADATA AND A TABLE OF CONTENTS OF A BOOK • Automated extraction of a metadata from PDF and DjVu. • Convenient editing of a metadata. • Editing and creating a table of contents in manual and automatic mode. • Synchronization of a metadata and a table of contents in iCloud. STORAGE • Locally on the device. • In the Cloud Storage (iCloud Drive, Google Drive, Yandex Disk). • Content server for accessing files on the device via a local network. • Import files from shared folders in the local network. • Export files.