I watched a interesting talk by the "untappd" social network creator Greg Avola (https://www.youtube.com/watch?v=isdUxWFSE50) this week. He described his experience launching a mobile enabled website and his attempts to encourage people to join the network and then regularly open up the site to interact with other members.
Once they decided to launch native apps on Apple and Android they saw new user take up go from around 1,000 per month to 23,000. That is a fairly substantial increase.
This reinforces something that we have seen time and time again with schools and especially busy parents. Yes the terms dates are on a pdf on the website, but will a parent spend the time navigating to your website on their phone to find what they are looking for? or do they just call the school office? I think that is why we have seen such a great a great response rate to our apps, it makes basic tasks like this much easier.