Anyone getting over-excited about the potential for music album-apps on iOS should read developer Marco Arment‘s latest blog post for a sobering dash of reality. In it, he outlines the difficulties of charging upfront for apps in a world where free and freemium are increasingly dominant business models. “Many people with iPhones and iPads full of apps have never bought a single paid-up-front one,” writes Arment, who came to prominence with his Instapaper reading app. “I’m sure of one thing, though: the market for paid-up-front apps appealing to mass consumers is gone. If you have paid apps in the store, you’ve probably seen the writing on the wall for a while… Paid-up-front iOS apps had a great run, but it’s over. Time to make other plans.” What about the implications for album-apps then? We suspect the direction may be towards free apps with all the extra content pointing fans towards a purchase of the actual music through iTunes, to play it from within the app (but also elsewhere).