Trump's iPhone has one app: Twitter

Top White House officials tell me the key to forcing a more disciplined President Trump (like the one onstage overseas) is limiting his screen time. In Trump's case, it's curtailing his time watching TV and banging out tweets on his iPhone.

Trump himself has been pushing staff to give him more free time. But staff does everything it can to load up his schedule to keep him from getting worked up watching cable coverage, which often precipitates his tweets. It has worked well overseas so far.

One fun thing: POTUS' current device is an iPhone with ONE app: Twitter.

House committees leading the impeachment inquiry against President Trump subpoenaed acting White House chief of staff Mick Mulvaney on Friday.

The big picture: This comes after nearly a month of White House refusals to comply with House investigations into whether Trump jeopardized national security by pressing Ukraine to interfere in the 2020 presidential election, and by withholding security assistance provided by Congress to help Ukraine, per the subpoena. The committees are demanding documents by Oct. 18.

• Stat du jour: 📉 U.S. economy adds 136,000 jobs in September, unemployment rate falls from 3.7% to 3.5%
• S&P 500: 2,952.01 (👆 41.38 — 1.42%)
• 1 2020 thing: 💰Elizabeth Warren's campaign raises $24.6 million in Q3, Steve Bullock raises $2.3 million
• 1 impeachment thing: 🏛️House Democrats subpoena the White House
• 1 tech thing: 🇮🇷 Microsoft says an Iranian group tried to hack a 2020 candidate
• 1 business thing: 🎨 Banksy painting sells for a record $12.2 million

Keep up with breaking news throughout the day — sign up for our alerts.

Sen. Ron Johnson (R.-Wis.) told the Wall Street Journal that he learned of a possible quid pro quo between the Trump administration and Ukraine's government from EU Ambassador Gordon Sondland.

The big picture: Johnson said that he pressed President Trump on the issue, which allegedly linked the distribution of $400 million in U.S. military aid with a Ukrainian investigation of former Vice President Joe Biden, in an Aug. 31 phone call. "He said ... 'No way. I would never do that. Who told you that?'" Johnson told the Journal of his conversation with the president.