Some of Sinelnikov's apps (on the left) compared to their similarly named App Store counterparts (on the right).

(Credit: CNET)

Apple has declared war on lookalikes in its App Store.

The company today removed a handful of iOS applications that bore a resemblance to more popular apps, and had climbed the charts as a result.

As spotted by TechCrunch, apps like Tiny Birds, Plants vs. Zombie, Numbers with Friends, and Temple Jump have been removed from the App Store. That's not to be confused with titles like Tiny Wings, Plants vs. Zombies, Words with Friends, and Temple Run, longtime crowd favorites and best-sellers that remain available.

The removals come on the heels of a report posted by The Guardian chronicling Anton Sinelnikov--the developer of these titles--as well as other developers that have created apps that customers can easily mistake for the real deal.

Nine of Sinelnikov's other titles remain available on the App Store, though none that could be mistaken for some on Apple's top selling lists.

Apple makes it at least partially clear that this behavior is not allowed, as per its App Store Guidelines, a rulebook the company introduced near the end of 2010 in an attempt to explain what it would and would not allow in its digital storefront. Two sections in particular detail where developers can get into trouble.

Under the introductory section (emphasis mine):

If you attempt to cheat the system (for example, by trying to trick the review process, steal data from users, copy another developer's work, or manipulate the ratings) your apps will be removed from the store and you will be expelled from the developer program.

And under the section on trademarks and trade dress:

8.5 Use of protected 3rd party material (trademarks, copyrights, trade secrets, otherwise proprietary content) requires a documented rights check which must be provided upon request

A fine line
Similarity among video games has long been a hot-button issue (no pun intended), with derivative works oftentimes being considered an important part of the ecosystem, something that can create genres, or transform them completely. Companies like Popcap games, for instance (now owned by Electronic Arts) have taken a stance that so-called clones of their games have provided valuable new ideas that the company may end up folding into future iterations.

All that said, there's a fine line, which is where things can get murky. That's been especially true in recent weeks, where the question of originality has been questioned by developers big and small.

For instance, developers like NimbleBit, the makers of Tiny Tower--which was Apple's 2011 iPhone game of the year--recently accused social-games giant Zynga of copying its game with an upcoming title called Dream Heights. Earlier this week the developer faced separate accusations from Buffalo Studios, claiming the company was ripping off its flagship Bingo Blitz game with a title called Zynga Bingo. There was also the reverse of that, when iOS game Vector Tanks was pulled from the App Store at the request of Atari for being too similar to 1980 arcade game Battlezone.

How much policing Apple will do on its own remains unclear. The company did not immediately respond to a request for comment on whether it is making any changes to its App Store Guidelines to spell out the rules differently, or if the pulled apps fell under one or more of the rules mentioned above.