ScreenHero is a downloadable app for Windows and Mac computers that allows you to collaborate one-on-one on the same app with someone else at a distance.
ScreenHero has recently added full support for Windows PCs and it now integrates a voice feature allowing you also to talk with the person you are collaborating with.
Your login credentials and session data are fully encrypted using a P2P TLS scheme (SSL based).
ScreenHero operates as a P2P app, allowing parties to hook up directly to one another, and resorting to its centralized servers only when a direct connection is not possible for some reason.
Via Robin Good