Sarah Tew/CNET

Google's video-streaming dongle just got three apps richer, as the video service Crackle, music-streaming service Rdio, and movie-and-TV digital shop Vudu gained support Monday.

After Google introduced its $35 Chromecast HDMI dongle (read CNET's review) to easily fling apps like Netflix and Google Play Music onto televisions, Chromecast was met with feverish consumer interest but an initial dearth of apps that may have stunted its usage as a go-to device to stream media. Since then, Google has opened up Chromecast to outside developers and worked with popular online-media companies to expand the number of compatible apps.

The news comes as competition in the streaming-media device market is growing, chasing the momentum in demand for watching online video. Amazon is widely expected to release its own such device later this week, going up against not only Chromecast but also Apple TV and Roku, the current leaders in the space.

Crackle, which is a unit of Sony's television production arm that is best known for its original Jerry Seinfield vehicle "Comedians in Cars Getting Coffee," said Monday that it is available on Google's Chromecast. The service also has licensed shows like "Seinfeld," "The Shield," and "Damages."

Crackle also appears as a quick-access button on Roku's remote, alongside such heavyweights as Pandora and Netflix -- an indication of its popularity among avid streamers, even if it's not a pure one. (Roku generates revenue by promoting content from its media company partners in various ways, so economics may have a role in which services get buttons in addition to popularity.)

The addition of Rdio brings Chromecast another service, like Pandora, that streams music through your TV system. Rdio Chief Executive Anthony Bay called it a milestone for the company.

Vudu, which started out as a streaming-media box itself and is owned by Walmart, is an online shop that sells and rents movies and TV shows.

Updated: With Rdio and Vudu apps.