The first thing you have to do is to download ePSXe software from Play Store as show in below picture.
Above picture is a free ePSXe Picture
After Installing ePSXe you will have it in your android device like below picture.
Now open ePSXe software in your mobile and it will appear like a below picture
Next Thing you need is off course games that are going to run on this emulator and for that we have to Run bios first, bios for ePSXe can be downloaded from site below.
1 site: http://www.freeroms.com/
Download Bios from the above site as shown in the above picture
Now bios will be downloaded as a Zipfile in your phone File Manager - Device Storage- Download.
Now as the game downloaded as a Zip File we have to download Winzip from Playstore to unzip the file.Winzip will be appeared on Playstore like below picture. Download it.
After downloading winzip, Open winzip and press storage as show in below picture
Now here you have to search for Download folder like below picture and get inside the folder.
After getting inside a downlaod folder you will see a Bios zip file. Select Bios File and press Unzip which is appearing just at the bottom of below picture.
Now select bios file as shown in below picture and press Unzip
Now press Storage as show in below picture
Press SD Card as shown in below picture
Now here you have to search for ePSXe and unzip the file inside it
Now open ePSXe again and press run bios, the phone will automatically search bios from your mobile and configure it for you like below picture.
Now you have to download games from them. Now follow all below pictures to download game from the site .
Press Playstation One from the site like above picture and now you can choose games from the list as show in above picture. Here in below picture we are downloading Bubsy Game
Now again the game will be downloaded in a download folder like bios file. Now again repeat all the steps i have shown you in above pictures to Unzip game file and now open ePSXe Emulator and press run game to run game on this emulator
Please Note: Some of the games are not going to run on this emulator due to incomplete roms on the sites but most of them are going to run so play them and enjoy classic games on your android devices
Now after following all the above steps you would probably running Play Station 1 games on your Android devices. The only thing you will found disappointed after running game is the keypad of games as keypad appears infront of the game screen. To find out how to setup PS4 controller on your android device so you can play games without on screen keypad with ps4 controller on your device watch out below video.