Dialogflow - Conversational UX Platform. (ex API.ai)

Handwrytten - Handwritten notes straight from your device. Huge selection of cards or design your own. Handwriting service integrates with 1000's of apps.

Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.

Mailjoy - Delightfully easy direct mail marketing. A DIY direct mail tool created for marketing and growth teams. Design, mail & track personalized direct mail postcards and letters. Digital marketers use Mailjoy to send data-driven mail campaigns.

Botpress - Open-source platform for developers to build high-quality digital assistants

The Simple Postcard - Text a photo to mail it as a postcard