Accessing Android Device File From PC Wirelessly

Step-by-step:

1. Install SSHDroid from google play:
SSHDroid
2. Open SSHDroid in your android device
3. Open file explorer (nautilus in Ubuntu or Windows Explorer in Ms. Windows)
4. Input the address in address bar PC as shown in Android device, It's like sftp://root@192.168.x.x:2222 password: admin
5. Explore your files in Android device from PC (like copy-paste and other)
6. Enjoy it!

Explore android file from Ubuntu PC