Kylie Jenner Gets Visit From Caitlyn During Her Makeup Tutorial

The 'I Am Cait' star admits she's jealous of her youngest daughter's eyebrows.

Even Caitlyn Jenner is getting makeup tips from her youngest daughter Kylie Jenner.

The 65-year-old I Am Cait star makes a surprise appearance in the the 18-year-old's latest makeup tutorial, and admits that she's pretty jealous of Kylie's eyebrows.

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"I hate your brows," Caitlyn says sarcastically. "Yeah, they're too perfect."

Kylie's makeup and style advice videos, which are available to subscribers of her new app, seem to be paying off. Alaxic Smith of CEO of told TMZ that the youngest Jenner sister is outpacing her siblings wen it comes to sign-ups. 

According to Smith, 891,340 users signed up for the Kardashian-Jenner apps within 24 hours, and Kylie has 74 percent of those subscribers. Khloe Kardashian was a distant second with 11 percent, Kim Kardashian followed with 9 percent and Kendall Jenner trailed with 6 percent.

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Kylie seemed pretty happy Thursday night when she started posting lots of pics and videos to her Instagram and Snapchat accounts. Wearing only a robe and nearly makeup-free, the Keeping Up With the Kardashians star is gleefully seen talking to her 25-year-old boyfriend Tyga in several of the videos.

"Running on no sleep man," she captioned one Instagram post. "I'm so excited for tomorrow!"

As far as the reviews of the apps, Kendall leads with four stars. That being said, ET points out that while Kylie's app may only have a 3-star rating, it has been reviewed at least twice as many times as all of her sisters, combined. That's over 800 ratings! Of those, she has more than 300 5-star reviews, which is, again, more than Kim, Khloe and Kendall, combined.

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During Vera Wang's show at New York Fashion Week on Wednesday, Kylie explained to ET why she and her siblings are charging fans a monthly fee of $2.99 to access their new lifestyle mobile apps. That comes out to a yearly fee of $35.88 per app.

"I put so much time into it," Kylie stressed, talking exclusively to ET. "And it's stuff that I would never choose to share in a million years, but deep down I want my true fans to know, like all my personal stuff and tricks -- stuff that I would never share on Instagram. So if they want to know real personal stuff that, like, makes me a little uncomfortable to share, then I don't think it's that big of a deal."