I'm looking to get feedback from students fairly seamlessly during a lecture. I know that there is a reluctance to raise one's hand (if part of a large audience), and my experience of such polling attempts (as a student) has been to break up the flow of a lecture quite considerably. Personally I don't want to get into a high-school teacher role of trying to tease out responses to questions so providing a platform for quick and semi-anonymous feedback would be useful.
But how to achieve this? Crucially most of the students are unlikely to have laptops, but are almost universally going to have smart phones. I don't want them to be struggling to take down the URL to a poll from a lecture slide, or having to log into some terrible VLE like Blackboard in order to get access to a link. QR codes could, in theory, be used to provide a link - but QR codes don't seem to be used much by casual users these days...
The reason for a digital rather than paper poll is that I can immediately respond to the results. Most of all I'm looking for as seamless an integration as possible into the lecture environment.