I've done a little sight-reading in the past but it's never been my strong point. I do understand the basics - the intervals, time signatures, etc. I'd like to get better at this by using an online tool or iPhone app. Something that presents you with a bar that you sing to yourself and then plays it for you would be good, but I'm open to hearing about other options. So far I've looked at Singsolatido - which is good for practicing intervals but I want to work on more than one note at a time.