KNFB reader try before you buy not working?

Hi, A few minutes ago, I was going to download the KNFB reader app to use the try before you buy option. However, when I found it by doing a seach, it showed up as $99.99. Also, the appstore said you could buy things within the app. I saw the app was updated on the second of this month, what's going on? I was going to try searching on my iPad, to see if it may have just been on my phone, but I don't have access to it right now, and I don't know if there is an iPad vertion of the app.