For the RF/microwave enthusiasts out there, you may recall the old HP Reflectometer Calculator that does conversions between SWR, Return Loss and calculated mismatch uncertainty.
Well, fast forward to the 21st century and this same functionality can be found in an iPhone ap. Agilent Technologies has a free ap available on iTunes that does these calculations and some other things like decibel conversions.
Check it out at here or just search for microwave calculator on iTunes.
– 73, Bob K0NR