Steam Friends (unofficial)

With this skill you won't have to start your PC to find out if any of your steam friends is currently online or playing anything.
After you first invoke the skill you will be asked to enter a setup page, input your steamID and select your steam friends you really want to be informed about by Alexa.
Your steam profile's privacy needs to be set to public for it to work.

This skill is in no way affiliated with valve. It's just a non commercial fan made app.