Pardon my terrible memory, but didn't POP create a customized iphone application several years ago for a Tessitura organization? Anybody remember who it was for? And/or anyone using one now and willing to provide some feedback?
I don't specifically remember an iPhone app, but I think they developed a mobile site for Seattle Opera (mobile.seattleopera.org).
I'd be very curious to see an app too. Have you seen the one for English Natl Opera? It's gorgeous, but I don't know who developed it. San Diego Opera has one as well.