I love Ukulele Underground. I came upon it accidentally when I was first learning and I've improved so much! You can play along; the chord diagrams right there on the screen. Before you know it, you're playing at tempo--I'm talking minutes, not hours! They choose cool songs with good arrangements. My favs are Fly Me To the Moon, Thinking Out Loud, and I Saw the Light. Thank you, Ukulele Underground!