HP 12C, fully functional or not?!

I had this app--or one exactly like it--three or four years ago. It was exactly like an HP 12C in every respect. But then I had to restore everything onto a new iPhone, and all of the financial functionality disappeared. I was left with an, essentially, four function calculator. So I wonder if this is just a technical glitch and the guy who wrote the program is sick/deceased and is not able to read these reviews? That is, maybe hes not aware of the problem. Or maybe he got sued by Hewlett-Packard? But theres something funny going on here for sure.

Erase that! I have found that the fully functional HP 12 C appears when you turn your iPhone sideways. Portrait, you have merely a four function calculator basically. But go to landscape, you get the full function calculator that I had a couple of years ago! Sorry about that but it appears other people have experienced the same "lack of functionality."

leesail about HP 12C Financial Calculator