Apple has caught the ire of some developers this week after it was revealed that all applications with integrated Web browsers will reportedly be rated for ages 17 and up, and that all such apps will not be entitled to promotional codes.

As first reported at The Unofficial Apple Weblog, the App Store’s new app rating system prevents developers from obtaining promotional codes for their applications. Such codes allow up to 50 free downloads for developers to distribute however they see fit, such as for publicity or promotion.

“As it stands, neither the 3.0 software nor iTunes display parental warnings when using a promo code to purchase apps with a mature (17+) rating,” TUAW writes, “so Apple has made the promo code functionality unavailable for apps that fall into that category. We were informed of this condition by a developer who prefers to remain anonymous.”

This has upset some developers, such as the creator of Instapaper and Tumblr, Marco Arment. The developer conveyed his frustration in a blog post Friday, saying he now doubts the viability of a business based on iPhone apps. Arment has expressed his displeasure with Apple before, specifically with regards to the iPhone maker’s alleged unwillingness to answer developers’ questions.

Now, Arment claims that Apple takes 8 to 30 days for review, and all Web-capable applications must come with nudity warnings, potentially limiting its audience.