How I Built the #1 App on The App Store (Twice)

Lobby achieved 500,000 Daily Active Users (DAU) and ranked #1 on the App Store in 5 countries. This was achieved through pure product-led viral growth without any paid marketing.

Before full-scale app development, Roger uses Protopie to create mock-ups and tests user reactions with TikTok ads. Validating at the prototype stage reduces unnecessary engineering effort.

Bro is an AI companion that floats on the screen, offering assistance within text messages and dating apps. A video on TikTok garnered 7.9 million views, leading it to achieve #1 on the US App Store.

In the idea validation phase, ads are the fastest means of feedback. While ads are unnecessary for scaling, initial ad investment of a few thousand dollars can provide instant feedback.

Lobby's growth turning point was the implementation of the "group picture" feature. Taking a photo simultaneously with everyone during a video chat and sharing it to Instagram or Snapchat stories improved network density.

Lobby's explosive growth in the Israeli market was due to a high percentage of users (60% compared to 20% in other markets) acquiring 5 friends on day one, leading to a 90-day retention rate of 25-30%.

In TikTok marketing, the "hook and demo" format is effective. Featuring a real person prevents swiping away, as viewers tend to scroll past videos that only show an app interface.

Online conversations often feel like conference rooms. Lobby was designed to recreate the college dorm lobby experience, avoiding awkward silences with background activities like YouTube and SoundCloud.

Successful consumer social apps require both "relationship density" and "temporal density." Real-time products necessitate users being online at the same moment.

AI companions should not replace real-world human relationships but rather create "context" to foster more genuine human interaction. It's important to use AI to create context, not content.