Nintendo subsidiary The Pokémon Company will release a paid iOS app, an interactive encyclopedia of the fictional monsters that make up the popular game series, on Friday.

Pokémon Zukan For iOS will let Pokémon fanatics browse an in-depth visual guide to the nearly 650 different characters. The initial download will cost 170 yen (about $2) and include data on 150 different Pokemon. To acquire the rest, users will have to buy them via four in-app purchases of 500 yen (about $6) each.

So far, it has only been announced for the Japanese market.

The very existence of this app is something of a big deal. Nintendo has assiduously avoided putting any of its games or characters onto game platforms that are not its own, and has repeatedly stated that it would not make iOS apps. But Pokémon Company, though wholly owned by Nintendo, has a bit more flexibility. In 2011 it released a rhythm game called Pokémon Say Tap?! for iOS.

But this was a free application that was only available for a limited time. However, releasing a paid-for application that directly competes with a Nintendo 3DS product is a different story.

We're still a long ways away from seeing a full Pokémon game on smartphones. It might never happen at all. But fans do now have the choice of buying the Pokédex 3D Pro app on a Nintendo system that costs a flat $15 versus one that costs $2 and has $24 in optional in-app purchases.

Nintendo will likely never report whether the Nintendo platform version or the Apple one makes more money – but it will know.