Smule, which makes a variety of music-related iPhone apps like Guitar!, Magic Piano, and AutoRap, has a new version of its popular Sing! Karaoke app out today with a major feature for the app: video. The new version of Sing! Karaoke, which features “a huge catalog of top hits” with instrumental tracks and lyric guides for singing along to, does three things with the newly added video feature. expand full story