PS: Post Scriptum is described as 'Secure your files and communication with the most advanced encryption system available in the market. Full anonymity, 100% security, ultimate privacy. Your photos, PDFs, passwords and communication fully encrypted at one place' and is a Encrypted Chat app in the file sharing category. There are more than 25 alternatives to PS: Post Scriptum for a variety of platforms, including Android, iPhone, Mac, Windows and iPad apps. The best PS: Post Scriptum alternative is Signal, which is both free and Open Source. Other great apps like PS: Post Scriptum are Telegram, Element, Tox and WhatsApp.