Emoticon Picker is a free and open source app that sends emoticons from your Android phone directly to your PC wirelessly.
First, you open the PC program (you need Java to make it work properly), then you open the app on the phone; the setup is very simple and automatic.
If you are a Windows user, you should disable your firewall to make the program work.
This app works from Android Wear to PC too!
Many thanks to Jovie Brett Bardoles, for the awesome UI and icon :)
Download program on PC: http://matteolobello.com/projects/emoticonpicker/cp/EmoticonPicker.jar
You can find the source code on Github (https://github.com/OhMyLob/EmoticonPicker)