You can also get official HP emulators for the iPhone. They were unmaintained for years but now they've been handed over to a new company who is updating them a

You can also get official HP emulators for the iPhone. They were unmaintained for years but now they've been handed over to a new company who is updating them again. https://apps.apple.com/us/app/hp-15c-calculator/id503720774 https://apps.apple.com/us/app/hp-15c-calculator/id503720774