RadaeePDF - RadaeePDF is a library for developers who want to render, manipulate, annotate PDF files on Android, iOS and Windows.
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
genei.io - AI-generated summaries for any article or research paper.
DjVuLibre - DjVuLibre: Open Source DjVu library and viewer
SignRequest for G Suite - Sign yourself or get documents signed Easy, secure, legally binding and free. SignRequest helps you sign online.
DjView4 - Standalone viewer for DjVu files.