This is the "Legacy" version of JRPN 16c. A newer version is available that's visually more faithful to a real HP 16c calculator. I recommend the new version, but I'm keeping the old version on the play store, because there might be some older phones that can't run Flutter apps.
Programmer's calculator based on Emmet Gray's WRPN 16c, which simulates an HP 16c. I modified Emmet's WRPN (with permission) so that it uses rendered fonts for the keys. This makes them look nice and crisp on high resolution displays.
I offer this software as-is, with no guarantee of any kind. The source is available on github. There's also a desktop Java version -- see https://jrpn.jovial.com/ for both.