Amazon introduced Thursday two gadgets similar to its voice-controlled Echo speaker, which can be used to check the weather, order Domino's pizza or hail an Uber car.

The Amazon Tap, a portable speaker that streams music, sells for $129.99. The $89.99 Echo Dot is a hockey puck-shaped device that responds to prompts to control smart appliances and connects to external speakers.

For now, the Echo Dot is available only to Amazon Prime members who already have the original Echo device and Amazon's Fire TV set-top box. The original Echo, launched in 2014, is larger and cannot connect to external speakers.

"Lots of customers that have ordered Echos and used Echos have told us that portability was a big use case," said David Limp, senior vice president of devices at Amazon, explaining the company's decision to develop the Tap, a soda can-shaped speaker that can connect remotely to music streaming services. "They want to take it on the go, and so Amazon Tap allows customers to take an Alexa end point and use it. It's completely battery-powered; it gives you up to nine hours of battery life when playing music and you just tap it, and then when you're in a Wi-Fi environment, you then have immediate access to Alexa.

"Dot was a little bit different. People love the magic of the far-field voice experience that they got with their Echos, but they found that they would love to use it with the speakers they already know and love and already own. And people's preference for speakers are very personal, and so Dot has a line out or Bluetooth capability built in to it so that you can connect it to the speaker of your choice." 

The gadgets are part of the company's efforts to position itself as a leader in smart homes, which let consumers to control various connected appliances like refrigerators and lights from a central hub such as Echo or a mobile phone.

Last year Amazon opened up Alexa, the digital assistant that powers Echo, to third-party developers and added hundreds of new features like access to music streaming service Spotify and integration with smart lights made by Phillips.

Amazon also announced on Thursday a special interface to allow thermostat makers like Nest and Honeywell to connect their appliances with Echo.

"Well, we've been delighted by how customers are using Echo throughout their house and Alexa," said Limp." You know the ranges in use cases. Certainly music is very popular, but also people are integrating to their smart homes to be able to control through our platform lighting, and now thermostats which we announced today, and they are also getting delighted by a lot of the third party, what we call 'skills.' They are basically developers developing new things that Alexa knows, and those range from music services like Spotify to just yesterday we announced a game that's been very popular in the last 24 hours that allows you to hunt down who killed Batman's parents," said Limp.

Amazon does not release sales figures for the Echo, so it is unclear how well the device is selling.

Other tech companies, including Google and IBM, are also racing to introduce products to control smart homes.

Amazon is also not alone in investing in digital assistants, which can provide valuable data to technology companies about their consumers' interests, preferences and spending habits.

Apple has steadily broadened Siri's reach since the first edition was released in 2011, while Google, Microsoft and Facebook are also continuing to develop their own digital assistants.

Limp said Amazon has been trying to improve Alexa's ability to identify natural speech patterns and accurately act on user prompts.