Hi, does anyone here know how I could create a continous playlist without any gaps? I know there are digital DJ apps out there but i am not sure which one to use. Any suggestions?

Surely that is just the loop feature of the player and not the the playlist itself ? There isn't a standard for playlists, but M3U comes close, but again, it's the player and not the playlist that has this feature. Most players will have crossfade options as well as song gap definition. This is a player preference, and not a play list preference. A playlist is just a list of songs, the player determines how the songs are played and not the playlist, it does not store preferences in the playlist.

I you want one mixed, with no stop in the beat, you'll need a DJ app and a little time to work it out and put it together, all your songs would also need to be around the same tempo. Virtual DJ is free for home users and is extremely popular.

Otherwise, it's normally possible to set the cross fade between songs in iTunes or any other player to give a continous flow of music.