This profitable iOS productivity app lets professionals sign PDFs instantly and securely from their iPhone, while also enabling them to edit and manage documents by adding signatures, initials, and stamps, tracking document history, and securely storing and sharing files as a lightweight, mobile-first alternative to traditional desktop PDF tools. Key Highlights ✅ Instantly sign PDF documents securely on iPhone ✅ Add signatures, initials, and stamps directly within documents ✅ Edit and manage PDFs from a mobile-first interface ✅ Track and manage document history for easy reference ✅ Securely store and share files without relying on desktop tools