Alternatives to SimplySign Desktop

Smart card libraries and utilities

Estonian ID-card drivers, authentication components & signing components

Multi-platform client-side cloud file encryption tool

Privacy-focused note taking app

Tool to flash OS images to SD cards & USB drives

X Certificate and Key management

Wallet desktop application to maintain multiple cryptocurrencies

Application for electronic signing of signatures

Connect to almost anything with a serial port

Shows a files cryptographic signing information

E-reader software

Free, open-source, and completely encrypted notes app