Updated from Jan. 5 with additional news.

A year-old finance alert app is hoping its newest feature will help investors stay ahead of the curve when President-elect Donald Trump logs on to Twitter (TWTR) - Get Report.

Since his election in November, Trump has posted negative comments about specific companies multiple times, causing their stocks to fall, sometimes significantly. The latest example came on Thursday afternoon when Trump tweeted critically about Toyota's (TM) - Get Report plans to build a new plant in Mexico, sending its stock down about 0.5%.

Other companies caught in the crossfire in the past -- such asBoeing (BA) - Get Reportand General Motors (GM) - Get Report -- have seen rapid dips in their stock prices following Trump's tweets. As a result, Trigger, a free app for iPhones that sends out personalized alerts for stocks they hold, has just added a 'Trump Trigger' that pings you when Trump has tweeted about one of your holdings.

"The Trump trigger was based on overwhelming customer demand over the last few months," said Rachel Mayer, co-founder and CEO of Trigger. "Since getting elected his words have much more meaning."

This week, Trump kicked off the new year by criticizing both Toyota and GM for selling Mexican-made models of their respective Corolla and Chevy Cruze vehicles in the U.S., and warned that they would be facing a border tax:

Toyota later fired back at Trump, saying that the company "has been part of the cultural fabric in the U.S. for nearly 60 years." The company noted that it "looks forward to collaborating" with Trump and his administration in order to look out for the best interests of both their customers and the automotive industry.

"Production volume or employment in the U.S. will not decrease as a result of our new plant in Guanajuato, Mexico announced in April 2015," the company added.

After Trump's tweet about GM on Tuesday morning, GM stock dropped about 1% in premarket trading, but recovered from the dip later in the day. In December, Trump blasted Boeing for the price tag on its 747 Air Force One plane, saying "cancel order," and Boeing's shares immediately fell nearly 2%.

"While it's no surprise that Trump has been actively tweeting since the election, no one anticipated that a single tweet could potentially eradicate billions of dollars in market cap from large companies," Trigger explained in a blog post.

On Trigger, users can set up personalized alerts to be notified if a stock falls below a certain price, if it hits a yearly low or a high or if it moves a certain amount during any given day. The user can then decide if they want to act on the trigger or not. "It monitors both users' holdings and their watch list," Mayer explained.

And with the increased "political tweet risk" due to Trump's outspoken posting style on the social media site, the company has adapted this service to give users access to the same kind of alerts, algorithms and models that hedge funds and Wall Street traders use to account for risk in stocks due to Trump's words. "We're trying to get the same service to everyday, do-it-yourself investors on their phones for free," Mayer said.

Trigger is hoping that this new feature will be the right tool for stockholders looking for new opportunities.

"The launch of our Trump trigger is the first step in our company's direction of using not just price-based data but relevant world events to condense into simple 'IF this, THEN that rules,'" Trigger noted. Mayer pointed out that the new Trump trigger is now already one of the most popular services on the platform just days after its launch.

Of course, things could all change once Trump is inaugurated on January 20.

In an interview with 60 Minutes after the election, Trump said that his use of Twitter would be "very restrained" after he takes over as president. Incoming White House press secretary Sean Spicer said this week that Trump's personal handle, @realDonaldTrump, would probably remain active, even as Trump takes control of the @POTUS handle from outgoing President Barack Obama.

"Of course, we don't know yet if he'll actually stop tweeting," Mayer said of Trump's Twitter activity post-inauguration. "I don't anticipate the [Trump trigger] will be less effective, though."

If Trump were to heed advice to use his handle less often after being sworn in, Mayer said that Trigger plans on adapting their Trump alert to monitor White House press releases, Trump's television appearances or other commentary from the President-elect to warn users about potential stock movements.

Additionally, the company is developing other triggers to warn customers about similar relevant real-world risks and opportunities. According to Mayer, Trigger has alerts in the works to monitor economic events like job reports, Fed statements, unemployment rates and SEC filings. The company is even developing alerts based on major weather patterns or what Warren Buffett is buying.

Another company is also reportedly looking to preempt potential Trump tweets. Snack giant Mondelez (MDLZ) - Get Report, which makes foods like Oreo and Chips Ahoy cookies, has been working on plans to have quick responses in place if Trump turns his attention its way, sources told Bloomberg.

Trump has been an outspoken critic of the Deerfield, Ill.-based company, accusing the company in August 2015 of taking away 1,200 jobs from the U.S. by moving Oreo production to Mexico. The President-elect said he would "never eat them again." In reality, the company only upgraded cookie and cracker production at an existing Mexican plant.

But like Trigger, Mondelez is not taking any chances. "There's no question they have a crisis plan in place," Richard Frisch, a crisis-communications consultant, told Bloomberg.

Mondelez did not immediately respond to a request for comment.