Send anywhere, a Korean app that has made file sharing between PC and mobile much easier. This app is totally free and easy to use. You can download this app from Google play store, and their official website.

How to use Send Anywhere:

You definitely need to use same network across your devices in order to share files, otherwise, it won't work. There's no need to sign in but if you want, you can definitely sign in. 

(1) Transfer:

Under the tab, you will find two options.

 (1a) Send: Here you can send you find. Just click on it and select the file, click on send, it will give you a QR code & a number. 
 (1b) Receive: You will tap on it in that device where you wanted to receive file. Scan the QR code or type the number in to start the process.
(2) History: Here you can see the files that you have sent or received. 

An app where you can easily share files between PC and mobile
(3) My Link: Here you can sign in.

Q&As:

Is the Send Anywhere app free?
Yes, send anywhere is free for Android, Mac, PC.