Let me start by saying I do generally understand copyleft GPL, but I'm having some trouble with this particular scenario. It's quite complicated to communicate but I'll try my best.
First I'm working on an app in iOS that supports Russian voice recognition. The engine I use is pocketspinx which uses a BSD license so all good there.
I am trying to use within my app a voice recognition acoustic model that is distributed under GPLV2. The model is from VoxForge. An acoustic model is kind of like a script that tells the app how to run.
It is located here : http://www.repository.voxforge1.org/downloads/Russian/Trunk/AcousticModels/
My understanding, and please correct me if I'm wrong is that I can not distribute this acoustic model bundled in my iOS app, though I would be able to if it had been licensed as LGPL instead. (Please tell me if this is correct)
My next question is whether I could download this acoustic model from within the iOS app and use it that way? The user would press a big download button, the acoustic model would be downloaded and then the system would work.
Last question is if the last thing is ok, am I allowed under GPL to rehost that acoustic on my own server (for faster download speed), and would that rehosting have to open to public downloads.