The Android and iOS markets are buzzing with voice-powered software applications. Some of these applications, though inspired from Apple's Siri, take voice assistance feature in smartphones to the next level.

When compared to the current benchmark in virtual voice assistant Siri, these programs do better in certain aspects, but lags behind it in some other factors. However, these programs are capable of challenging the domination of Apple's Siri.

Here are the top five virtual personal assistant alternatives to Apple's Siri.

1.      Evi is almost like Siri, but is different in intelligence, processing and accent.

Evi has a British accent and uses natural language processing and semantic search technology.  When compared to Siri, its processing skills are superior and answers are more relevant.

Evi goes beyond just matching the words in the search phrase and analyses the information gathered from multiple sources to come up with the most relevant answer to the query.

 Evi's data pool is connected to popular applications and APIs like that makes it more interactive and useful. For example, if you are asking for a particular food, Evi will give you list of the nearest restaurants which provide the item, In addition, it can also make reservations in the restaurant.

Evi outshines Siri in giving accurate answers to more complex queries. It can run on even older iPhone models and is worth using in Apple iPhone 4S too. Though Evi had initial problems with its server capacity, now the problems are sorted.

2.      Sara is an alternative to Siri for all iOS devices. Developed by a Vietnamese team, it can be used in several countries and is available in more than 37 languages.

Sara does a multitude of tasks from search, controlling PCs, reading newspapers, reading barcode, scanning along with other basic features like social media sharing.

It saves the iOS users from the trouble of proxy servers and jailbreaking to make Siri work in their phones.  Sara also is open software and it can be taught by any one.

3.      Iris is an Android alternative to Siri. It is described as the best application for an interactive user, who like to chat in a trouble free way. Though it is simple, yet it lacks integration in comparison with Siri. It has all the basic features of other virtual personal assistants.

Iris invited trouble for its reportedly racist and anti-abortion answers to certain questions posed by the users. Its developers are sorting out the problem that triggered from its integration with Cha-Cha, an answering community which was providing the knowledge base to the program.

 4.      Speaktoit is a real challenger for Siri in the iPhone, and it has an Android version too.  It is more stylish and allows customized avatars. The best feature is it has an inbuilt social media sharing feature and does not depend on text messaging service to share updates.

Instead of listing the results, Speaktoit speaks out the results, making it more fun to interact with.

It can be downloaded from iTunes. There is also a special Valentine's Day offer - first 100,000 people can download it free on the V-Day.

5.      Tellme is a Windows alternative to Siri. Though Windows have introduced it as a competitor to Siri, it has limited features.  

The user interaction of Tellme is similar to that of Siri but its search results are connected only to the Bing pool.

It has an advantage over other similarly placed products for its multi-platform usability. The application can be used on Windows mobile, TV, Windows 8 and other compatible products.