SportsTap has a widget, but the scores are way behind real time. LiveScores has more up to date information, but no widget.
The SportsTap widget may be behind. I don't really use the widget, but open the application as needed. Refreshing now within the app brings sports scores relatively close to when they happen (at least for me).
The thing I like best about sports tap, is that I can have it set to send me alerts for the teams I like such as start of game, scores, end of quarter scores, end of game scores. I found that the alerts matched pretty close to when my OSU Buckeyes scored (at least in football). The alerts also let me not keep hitting refresh within the program.