ES File Explorer lets you look at the files you have in the device. You can use it to manage the files (delete, copy, email, share on social media etc)
Brief overview for ES File explorer's interface:
If you seem to get "lost" in the exploration, simply select "Local" from the tabs and select "Home"
You can also track where you are by the breadcrumbs as labeled below.
To manage files, simply press the target file and hold until the icon is selected. Use the options for management as noted below.
You can manage your files using the options shown on the bottom of the ES File Explorer screen. You can add another folder, add another file, add an FTP server or connect to the cloud drive of your choice.