Best Black Friday deal so far: $150 50-inch TV

​LOS ANGELES — The Black Friday deals are still coming in, and TVs are leading the pack in big bargains.

The catch is that they'll go fast, both in-store and online. And in one high-profile case, the deal may only be offered via a mobile app.

Dealnews picks a no-name, 50-inch flat-screen TV selling for a rock-bottom $150 on Amazon on Nov. 26, as its overall top deal.

The site says this is the cheapest 50-inch TV it's ever seen; $240 had been the previous ceiling. It also beats every other Black Friday deal it's seen for a similar size HDTV.

However, don't look for this if you're shopping on the computer. Amazon will only offer the TV via its mobile app, says Dealnews. "We'd never seen this before," says Benjamin Glaser, features editor for Dealnews. "But as Amazon goes, so goes the industry. You may see other retailers throwing in mobile-only deals this week too."

Amazon�s Black Friday deals actually start this week

Most deals mentioned here are only available Thursday and Friday of Thanksgiving week. A Toshiba HDTV that's just one inch smaller will also sell for $150 in limited quantities at Best Buy.

And if you want to go big, a 70-inch Vizio TV will sell for $898 at Walmart. Dealnews says this is $300 less than the previous low for a 70-inch model. A search for 70-inch Vizio TVs on Bestbuy.com shows a range of models currently from $1,365 to $2,789.

While most of the deals have been announced, Glaser expects further price-chopping to begin Thursday. "You'll see retailers price match and undercut each other with live updates," he said.

Other Black Friday bargains:

-- Smart TVs. Among the other hot TV deals is one at Walmart that could catch the eye of those seeking a second or third TV for streaming video, the $125 32-inch TCL smart HDTV with built-in Roku functionality for streaming Amazon, Netflix and other video services. The display's previous low price was $180, Dealnews says. Elsewhere, Best Buy offers a low-cost entry to 4K Ultra HD video with the 40-inch Samsung smart TV for $449.99 among its pre-Black Friday deals.

-- Streaming media players from Roku and Amazon are being offered for doorbuster prices. The entry-level Roku, which normally sells for $50, is being discounted to $20 at HHGregg, while Amazon's Fire TV streaming player, normally $99, is discounted to $75 on the company's website.

-- Smartphones: Consumers want to buy phones as gifts, but get hung up on the cost (the iPhone 6S starts at $650) and springing for a wireless contract. This year, Wal-Mart is offering a $250 gift card for the iPhone 6S, bringing the effective cost down to $400. And Staples trumps the iPhone with $500 in credits for the Samsung Galaxy S6, with Verizon service, which Dealnews says is the equivalent of a $500 rebate.

“We weren’t expecting any deals on smartphones,” says Glaser. “So this is a big surprise.”

-- Tablets: Target is offering a $150 gift card with the $499 purchase of the Apple iPad Air 2, bringing the effective price to $349, while Meijer has a $125 store credit for the $350 iPad Mini 4. The lowest priced bargain tablet has to be Amazon's 7" Fire tablet, selling for just $35.

Follow USA TODAY tech columnist Jefferson Graham on Twitter, @jeffersongraham.