California-based UberMedia, which has made several apps for the Twitter platform, is said to be working on a competitor to the micro blogging website, which recently rejected two of its apps.

UberMedia, owned by Internet entrepreneur Bill Gross, is a developer of applications and web-based services that make it easier for users to find, follow and communicate with others on Twitter and other social media platforms.

UberMedia applications now include UberTwitter, Echofon and Twidroyd, which are leading Twitter apps on the BlackBerry, iPhone and Android platforms, respectively.

Twitter's new rival site may attract users by exploiting Twitter's common disadvantages, such as its restriction on the length of a message (140 characters) and how it can be confusing to newcomers, CNN reported citing people familiar with the plans.

Meanwhile, UberMedia has emerged as rival to Twitter after building a large portfolio of Twitter-related services through acquisitions. In February, Twitter suspended two of UberMedia's apps - UberTwitter and twidroyd -citing that they have violated Twitter's policies.

A recent data from Sysomos shows that 42 percent of tweets in Twitter were made by non-official apps such as UberSocial and Echofone, which are owned by UberMedia.

More enthusiastic and power users are using non-official services such as TweetDeck, UberSocial and Seesmic as many of these applications have many more features than Twitter.com despite recent improvements, Sysomos said in a blog post.

In addition, developers were little bit annoyed over a recent Twitter memo that asked the developers to code software that presents data in a new and interesting way rather than the traditional list format seen on Twitter.com.

Developers who felt they had helped Twitter grow were not too happy about the memo that discouraged them to develop standard client applications.

We want to empower our ecosystem partners to build valuable businesses around the information flowing through Twitter. At the same time, we aim to strike a balance between encouraging interesting development and protecting both Twitter's and users' rights. So, we've come up with a set of Developer Rules of the Road (Rules) that describe the policies and philosophy around what type of innovation is permitted with the content and information shared on Twitter, Twitter said in a blog post

The Rules will evolve along with our ecosystem as developers continue to innovate and find new, creative ways to use the Twitter API, Twitter added.

Till now, Twitter has triumphed over its rivals, including Google Buzz and FriendFeed, and is estimated to have more than 200 million active users. Last week, Twitter said users were posting 155 million tweets a day, up 282 percent from last year.

Nevertheless, a Twitter rival from UberMedia may pose a serious threat to Twitter as its apps are already familiar to many users and could attract their customer base. Also, such a service would allow users to post messages on Twitter as well as on the new platform.

But, for UberMedia, it is not easy to develop as well as establish itself as a competitor to a giant like Twitter which would be an uphill task.