Adam Schwabe (@adamschwabe on Twitter and a former colleague at IBM) has a good rundown on the cost of developing an app here: The Race to the Bottom for Native Apps | Teehan+Lax.
Any organization considering developing an app would do well to read this first in order to better understand what they are getting into. Adam is not just passing on what he has read elsewhere: he has strong experience with developing mobile apps, including the successful Rocket Radar. Take a look.
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