Here are all the endings and achievements. Needless to say, major spoilers!

Endings:

Ending 0 - Refuse to pick up the phone from 4885 enough times
Ending 1 - Pick up and talk to the mother when she calls
Ending 2 - Call 1818 after getting the objective for finding what the mysterious numbers are
Ending 3 - Call the reporter at 0987 without activating location services
Ending 4 - Find evidence on Dickey and break into his private picture folder
Ending 5 - Call the reporter at 0987 after activating location services
Ending 6 - Connect over bluetooth with code 1015, then push the big red button some time during the 5th of November ingame time (you have to wait 2.5 realtime hours)
Ending 7 - Connect over bluetooth with code 1015, then do not push the button and let the game clock elapse to 6th of November (you have to wait 26.5 realtime hours) (not tested)
Ending 8 - Enter 4989 as unlock code, write anything with "knock" in it, pick blue pill
Ending 9 - Enter 4989 as unlock code, write anything with "knock" in it, but on the pill screen, exit the game by pressing escape, then start it up again
Ending 10 - Enter 4989 as unlock code, write anything with "knock" in it, pick red pill
Ending 11 - After getting the fourth ending twice, you will have an extra law in your law book which can be used for immediate execution. Use it.


Achievement non-endings:

1 - Patriotism Medal - Call any of the friends after finding details about the gathering
2 - Emergency Call - Dial 911 and talk to the dispatchers
3 - Stanley - Drag main menu to left, click the 430 icon fifty times
4 - Peeping Tom - Break into Twitter account
5 - Please, Don't Touch Anything - Activate the Bluetooth connection with code 1015 and get a shiny red button
6 - Busy, busy, busy - Break into Facebook before finding the owner's name and phone number
7 - Non-Violence - Stay on the phone unlock screen for 5 minutes
8 - A blood hound - Get the fourth ending twice