PrivateMark

About

PrivateMark operates entirely on your device without any servers or user accounts, focusing on two primary functions. First, it traces leaks by embedding an invisible watermark unique to each recipient before you share documents like photos, PDFs, Word files, or presentations. If a copy is later leaked, you can submit it to the app to identify the source. Second, it offers a Hidden Photo feature where you can send an image that appears as a harmless cover to everyone; only your trusted contact using PrivateMark can unlock and view the actual photo, which is secured with AES-256 encryption.