While it does not solve your question, I use Rocket Calculator (
https://itunes.apple.com/us/app/rocket-calculator/id484673201?mt=8) on both my iPad and iPhone while at the field. It's very helpful especially when I am RSO. It does things like altitude prediction, drift distance, thrust to weight ratio, ejection charge size, etc. You can change the units to pretty much whatever you want.
On the altitude prediction screen I take a screenshot once I have it all set up so I have a record of the results. It could be a lot more useful by allowing for stored rocket parameters which for this program is really just tube size and weight (and CD). But it does have a pretty good built-in motor database which really helps.
It's $4.99 which seems expensive for an iOS app but as much as I use it I feel it is well worth the price.
Tony