If you think that you need some fancy applications to tranfer files from your laptop/computer to mobile, than you are wrong.
All you need is
NOTE: Your laptop and your mobile phone should be on same network
Open your terminal and execute this command.
If you are using Python3:
python -m http.server
If you are using Python2:
python -m SimpleHTTPServer
<IP_Address>:8000 in your mobile browser to access the files in the directory where you ran the above command.
If you don't know your IP than follow this steps:
Go to System Preferences -> Network-> You will see your IP address there
Suppose your IP address is 192.168.0.1 then open mobile browser and type
192.168.0.1:8000 to access the files.