How to recover my Voice Memo recordings

I had long and valuable voice memos that I recorded on my iPhone. I went to use that app today and did not find it on my phone. I went to the App Store and when I downloaded it it told me that I could have a free trial but that I would start paying for it in three days. I see that all the sites say that it is free on the iPhones. How do I get the free app back and how do I recover my valuable recordings?