There’s a quiet but growing corner of social apps that’s taking off on TikTok.
Gen Z isn’t just scrolling for events anymore: they’re downloading apps that let friends share calendars, spot overlapping free time, and lock in plans.
Think Google Calendar, but prettier and way less corporate.
Some of these tools cater to businesses and big gatherings. Others zero in on tight-knit friend groups… and a few get even more niche with how they pitch themselves on TikTok.
Let’s break down three of them:
What they built, how they did it, and where they’re (likely) headed next.
Partiful
Hard to believe, but Partiful debuted in 2020… right in the middle of COVID lockdowns.
Princeton alums Shreya Murthy (CEO) and Joy Tao (CTO) not only kept the app alive, they’ve grown it by more than five million users since.
• 200K downloads last month
• #18 in Lifestyle (US)
Partiful jumped on social early, spinning up 24 TikTok and Instagram Reels accounts and pulling in 31.1 million views in just six months.
A few clips got a paid push, but most traction came organically from ambassador posts.
Every viral hit follows one of two simple formulas:
1 Close-up selfie (classic UGC).
Three-second head-shot, then a laptop screen-record showing the invites the creator sent or received.
The app name sits in the top-left corner, but no one ever name-drops it in the video or overlay text (some just tag @partiful in the caption).
Cue the perfect outcome: comment sections full of people asking, “Wait, what site is this?”
2 Faceless invite
They soon learned they could ditch the selfie clip and open with the screen-record instead.
The trick is that every invite has to hit Gen Z vibes: cute fonts, chaotic emojis, or one unhinged detail that makes viewers pause and comment.
A few hooks that crushed:
“me and my best friend send each other personalized invites just to hang out. and that basically sums up our friendship” 4.6M views and 3.5M views
“BRUHH this is the invite my mom sent to my friends and family for my grad party” ???????? 707.8K views
“girls… let’s normalize sending our friends invites for LITERALLY everything” 689K views
They recycle these hooks across different ambassador pages and in both ugc and faceless edits.
Want to track their latest numbers? Check Shortimize’s public collection: here.
…and final shoutout to their main account, tt@partiful.
They’ve gone quiet on their own feed since April 2. Ambassadors are bringing in new users faster than the brand account ever could.
For the three years before that, the main page was their testing ground. Each post taught them what would later become their highest-performing ambassador formats.
Biggest stunt so far:
Last October’s Timothée Chalamet look-alike contest in NYC. Hundreds showed up (including Timothée himself) and one of the three recap clips popped off with 4.2 million views.
Howbout
Launched in 2020 by uni friends Neil Tanna, Jake Jenner, and Duncan Cowan.
Now pulling in 350 K+ new downloads every month and hovering around #20 on the App Store.
Raised an $8 million Series A last August.
They’ve had a branded TikTok since day one, mixing faceless edits with creator-led clips… but that’s old news.
This year they rolled out a fresh network of ambassadors, and the numbers already speak: 193.6 million total views (seems mostly organic; with likely some ad boosted videos).
Skip the usual UGC videos and pump out UGC slideshows. Even quicker to crank out at scale, and they’re hitting just as hard.
Here’s how it works:
Slide 1: A close-up headshot of the creator, hitting the classic ambassador faces: wide-eyed, jaw-dropped, hand-over-mouth + a punchy text hook on top.
Slide 2: A low-key call to action. It’s a screen grab of the shared Howbout calendar that pays off the hook, but the app name never appears.
Slide 3 (optional): Another creator shot. Usually a friend-group photo to show the plan in action.
A few ambassadors are already breaking through:
| Account | Total views | Start date |
| tt@monicashowbout | 5,000,000 | April 14th |
| tt@tee.howbout | 2,900,000 | March 20th |
| tt@ciara.howbout | 485,100 | March 25th |
You will find all here.
Here are the hooks that lit the fuse on their first viral clips:
| Some of yall don’t have a shared calendar with your girls | 3,200,000 views |
| How I sleep knowing…… | 1,000,000 views |
| i told him that i was scared he would leave like everyone else | 664,600 views |
| when my toxic relationship ended i couldn’t stop wanting him back | 478,400 views |
| Bestie can we get this pls? | 280,400 views |
| not falling in love ever again. | 240,300 views |
| did you hear about what she did | 77,000 views |
| app of the summer >>> | 52,100 views |
Each line taps a distinct emotion.
Hooks 1, 5, and 8 stoke straight-up FOMO.
Hooks 3 and 7 dangle just enough “wait, what happened?” drama to feed viewers’ curiosity.
Even though Howbout is built for friend groups, the team clocked that breakup-and-couple storylines pull bigger numbers… so they leaned in.
And they’re not the only ones catching on…
Outside
We’re closing off with a quick analysis on this third app.
Outside has been slowing down lately, monthly downloads now sit below 5K and revenue has been flat for months.
To stay relevant, the team ditched the “calendar for everyone” angle and leaned hard into a tighter lane: couples in long-distance relationships.
Oddly enough, their website and App Store page still read like any standard shared-calendar app.
On TikTok, Outside pushed just one angle: long-distance relationships.
They rolled out a small ambassador squad in mid-2024.
The standout is Nessa, the same creator behind @nessyandruby who also hypes Couple Joy…
…and she’s now their only member still posting:
Her videos pull in 19.5 million views and an impressive 15.9% engagement rate.
She promotes Outside exactly the way she pushes Couple Joy… sometimes even re-using the same clips. The only things that change are a fresh hook and the new app demo.
All that changes is the hook (slightly) and the app demo, of course.
Outside signed seven other ambassadors, but they stopped posting early this year. Together they earned 22.5 million views, with 88 % of that coming from tt@nessarene_me.
Here are Nessa’s top-performing hooks:
• “When long distance gets difficult remember that” => 2M views
• “For everyone that’s trying to do long distance, always remember…” => 1.8M views
• “Biggest long distance tips” => 1M views
• “POV: your long distance bf made you download this to stay closer” => 873.7K views
• “Long distance is hard but not everyone can say that they loved someone deeply enough to be spend lots of days alone in exchange for a few days together => 823.8K views
By the way: if you missed it, we’ve rounded up winning/viral hooks from top social apps, and you can download them for free right here.
See you tomorrow!
The Social Growth Engineers Team.
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