ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
LightShot - The fastest way to take a customizable screenshot.
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.