I'm using 11CSciCalc on my MotoG7power. It's good (at least for keyboard layout and key-function -- haven't had occasion to try out its programmability for compatibility), but without the tactile feedback of the real buttons I have to visually monitor what actually gets entered, so I can't drop fully into the problem domain, not like I can with my HP11C.
It's my HP41CV that basically never gets used. Back when, I wrote a program on it, 'ampsr', to calculate ideals and then find the closest standard-value matches for a three-resistor attenuator network used as the gain-and-offset control of an opamp amplifier; it took 16 minutes for my HP41CV to arrive at the answer, and that was just selecting among the E24 "5%" standard-value array. My later Perl version, by comparison, is all but instantaneous even working with the E96 array and running on a 400MHz box. The HP41CV's programmability was great for its era; not so much, now.
It's my HP41CV that basically never gets used. Back when, I wrote a program on it, 'ampsr', to calculate ideals and then find the closest standard-value matches for a three-resistor attenuator network used as the gain-and-offset control of an opamp amplifier; it took 16 minutes for my HP41CV to arrive at the answer, and that was just selecting among the E24 "5%" standard-value array. My later Perl version, by comparison, is all but instantaneous even working with the E96 array and running on a 400MHz box. The HP41CV's programmability was great for its era; not so much, now.