Miro Startup Program - $1000 to set up team collaboration
Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Aircall for HubSpot - Document and organize every phone call instantly in HubSpot
Mediamodifier - Create beautiful designs and product mockups in seconds.
Intercom on Starting Up - A book about growing a startup
mockDrop - Is a webapp for creating free device mockups including your screenshots.