Will not work. – Bob Books Reading Magic #1 Review

I was excited to see that Bob Books had an app so I purchased 1 and 2 for my 1st Gen IPad last year. It worked fine and the kids loved it. I added two iPad minis so more kids could play. Last week, I purchased the sight words as an add-on to my other games. Now Bob Books 1 no longer works on my 1st gen iPad because it is trying to install the new version. HOW do I get my old version back? It is very frustrating because now the kiddos who use the 1st gen IPad are even more limited.
Review by Kindergartencatlady on Bob Books Reading Magic #1.