JRPN – Jovial Reverse Polish Notation Calculators (HP-15C and HP-16C simulators)

It available for Web and as apps for Android, Linux, Windows, MacOS & iOS.[0]

For Android Both, JRPN 15C and JRPN 16C, also available in IzzySoft F-Droid Repo.[1,2]

[0] https://jrpn.jovial.com/#Install

[1] https://apt.izzysoft.de/fdroid/index/apk/com.jovial.jrpn15

[2] https://apt.izzysoft.de/fdroid/index/apk/com.jovial.jrpn2

Excellent!

For fans of HP15C/16C, this is a near exact, beautiful reproduction/simulation. This app completes my phone.