Apps to Fill PDF Forms

PDF Chain is a user-friendly graphical interface (GUI) for the powerful command-line PDF Toolkit (pdftk). It simplifies common PDF manipulation tasks such as merging, splitting, collating, encrypting, and managing metadata without requiring direct command-line interaction.

qpdfview is a lightweight, tabbed document viewer based on Qt. It supports PDF, DjVu, PostScript, and other document formats, offering features like annotation, form filling, and a clean, customizable interface for efficient document management.

Okular is a versatile document viewer from the KDE community, supporting a wide array of file formats including PDF, EPUB, DjVu, and TIFF. It offers intuitive navigation, robust annotation tools, and features like text selection and saving, making it a powerful tool for handling diverse document types.

PDFTK Builder is a free, lightweight graphical interface for the powerful PDF Toolkit (PDFtk). It simplifies common PDF tasks like merging, splitting, reordering, and encrypting PDF documents through an intuitive graphical user interface, making complex command-line operations accessible to all users.