Add 'previous key' on on the player's lock screen widget and File

Components

Simple music player is a nice music mobile app that has many good features with a nice sound production, with lots of users around the world.

Proposal

the simple music player's lock screen widget ought to have the previous track selection key just as it have the next key. i therefore propose that this great feature be added to the player.

i also propose that the ability to read all the folder in all the storage in the device , both external and internal storage. and this can be achieved by adding a button in the menu that should be called "file".
with the addition of this 2 great feature, this player will be very good to go.

Mockups / Examples

the previous key as it appeared in vanilla Music player

how it should look in simple music player.

the file option

Benefits

the previous key will help the user return to the previously played track from a luck screen without passing through the stress of unlocking the screen, maximizing the app before going to the previous track.
the file option will help the user access to the phones folders, play music from folder of choice