Don't buy at the moments – Preposition Remix Review

Just downloaded this app today (2/212). Do not buy at the moment as has a major bug. See the other user's report of the same problem back on November 18th. It does not recognize when a correct response is selected. Happened when I was working on concepts behind and in front. I have written to company to ask if it is going to be fixed ASAP. Will hopefully be able to write a better review in future if this problem is fixed, but right now it is not useable.
Review by SLPworld on Preposition Remix.