Easy Message - Easy Message app comes up with features to help users in effortlessly sending text messages to a phone number, which is not in the contact list.
ProtonMail - Secure email with absolutely no compromises. Get your free encrypted email account today.
Message Peeping Tom - Message Peeping Tom is an app by HSTAR, offers features that let you read your messages without giving the read report to the sender.
Enigmail - Security extension to Mozilla Thunderbird and SeaMonkey
WhatsRemoved+ - WhatsRemoved+ is a mobile tool developed and published by Development Color for Android devices only.
Skizzle Email - Skizzle is the most secure way to share end-to-end encrypted files through email, backed by blockchain