Try Plickers to mobile, multiple choice questioning.
Go to http://www.plickers.com to set up and then download the Plickers app from the iOS or Google app stores.
Download the basic Plickers cards, for scanning, from https://www.plickers.com/cards. These come in various sizes and shapes to suit all learners. In the app, create a question to ask the group. Tell the learners to rotate their cards so their answer is at the top of the card, then using the phones camera, scan the groups responses. The results will appear real time on your screen. On the website you can even assign the cards to individual learners.
(Images from Google store)