Some people tell me they struggle to find all the 3 endings, which is a pity as I think it really is a nice thing to see them all.
I’ll try give you a few hints that hopefully won’t spoil all the fun for you.
spoilers below, please highlight the text to show the solution:
Talk with all your chat contacts. Some of them will eventually invite you to the party.
When you’re invited just go out.
There is a bug in the original jam version (corrected in version 1.1.4 and in Web version on Newgrounds) that makes it impossible to get this ending if you have talked on the phone. So if you’re playing original version, do not talk on the phone.
Ending 2 and 3
Some of the contacts will suggest contacting people outside chat. Don’t forget that your telephone is in your bag and that you like to look outside the window from time to time. When you’re invited just go out.
You could also consult this complete video walkthrough made by aWalkthroughLife:
Regarding Newgrounds medals, you’ll get 4 medals if you find all the solutions.
“fresh air” medal can be obtained by (highlight the text mouse):
“Contact Rockin’ Dave” can be obtained by (highlight the text mouse):