I am no hacker/developer. This is just to share my experience. I am not responsible if you mess your device up.
Perquisites (what I used):
Nexus 7 (rooted) Android 4.3.1
Nexus 4 (rooted) OmniRom Android 4.4.2
Windows PC w/ AndroidSDK (you only need adb.exe)
Android Terminal Emulator installed on both devices. Available on Playstore.
Open Android Terminal Emulator on the Nexus 7.
su adb kill-server HOME=/sdcard adb start-server
Connect the Nexus 7 to the computer and run the “adb.exe”. The following code will download the key to the “adb.exe” directory.
adb pull /sdcard/.android/adbkey.pub
adb push adbkey.pub /sdcard
Now you can either use Android Terminal Emulator on your Nexus 4(which is what I did) or “adb shell” on your computer. Simply append the key to the “adb_key”
su cat /sdcard/adbkey.pub >> /data/misc/adb/adb_key
To start ADB over Network on Nexus 4
su setprop service.adb.tcp.port 5555 stop adbd start adbd
adb connect 192.168.1.100 adb devices
Remember to switch off "ADB over Network" on Nexus 4
su setprop service.adb.tcp.port -1 stop adb start adb