48-ish units for Prime?

[cvicisso]

Greetings - I'm new here, but have been using HP calculators (and RPN) for a long time (28C, 32SII, 48gx). I'll try to keep this initial post short...

I have a son who just started 8th grade and is taking HS-level math classes, and plans to attend either the local 'Math & Science' Academy or the IB HS next year. Although I know it's early, he's leaning towards engineering. I have been doing WAY too much 'calculator' research in the last year, but I think I've settled on the HP Prime as the ONE tool that can best get him through the next few years - including (and probably most importantly) the SAT. I know I probably won't convince him of how awesome RPN is (otherwise I might try to push the 50g on him!), but even without using RPN, the Prime outweighs (slightly) anything TI offers - especially considering the Nspire CAS cannot be used on IB exams (which he will be taking if he goes that route).

Ok, with that background out of the way, the real question I have is this: Can I install any sort of program (app?) on the Prime that comes even remotely close to the usefulness of the 'Units' function(s) of the 48-series?? I used a 48gx in college (science degree) and used this feature CONSTANTLY. I STILL use it on my 'virtual' 48gx on my phone a few times a week. I love the ability to be able to choose the 'family/flavor' (Length, volume, speed, etc), then the unit itself (without TYPING the unit!!), and then easily CONVERTING to the desired unit - again, with a soft key (no need to type it out).

I would gladly pay for such an app.

Thanks in advance for any help!