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A tiny cautionary case: an AI-built English-learning iPhone app put about ¥100K into Google Ads and ¥13K into Apple Search Ads, and had made $11.
~¥100K Google Ads + ~¥13K Apple Search Ads · 17 Apple-attributed installs at ~¥750 each
“Building is easy now. The next contest is how you reach people.”
Fewer bars = easier, cheaper, or faster for an AI-assisted solo builder. Editorial judgments based on the case details.
Kaz, a former engineer who has spent 12 years in video work, began making iPhone apps with AI after looking for a reward-sticker app for his children. That first project, Puniche, led him to release roughly ten apps in two months. Kankaku Eigo, his English-learning app, became a clear lesson in distribution: he put about ¥100,000 into Google Ads and ¥13,000 into Apple Search Ads. Apple attributed 17 installs at roughly ¥750 each, while Google installs could not be measured. Current sales were $11, and Kaz described the campaign as a loss. Across his apps, he had spent about ¥200,000 on advertising over two months. The episode opens his 90-day attempt to build income beyond video work through apps and YouTube. His stated combined app-and-YouTube target is ¥150,000 per month by day 90; that is a goal, not achieved revenue. The useful case is a fast solo build followed by a costly, still-unproven acquisition test.
Start Kankaku Eigo's first customer cohort with ten learners who share one study moment. Narrow the promise to five minutes of speaking practice before work or a parent's after-school routine, then build the App Store page around that outcome.
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Data credibility: Kaz reports these figures on his own YouTube channel; they are founder-reported and unaudited. He reports $11 in current sales, 17 Apple-attributed installs at about ¥750 each, roughly ¥100K spent through Google Ads and ¥13K through Apple Search Ads for Kankaku Eigo, and about ¥200K in advertising across his apps over two months. Google installs could not be measured. These figures describe a loss-making test, not verified market demand or recurring revenue. The combined ¥150K monthly app-and-YouTube figure is his 90-day target, not achieved income.
The first dollar has already appeared as $11 in sales. The next goal is a repeatable purchase; a single receipt is a weak signal.
Build a growth loop around visible learner progress. After a week of completed lessons, let a user share a small streak card or invite a study partner into the same challenge.
A low-feedback stretch is normal for an English-learning app launched into a crowded store, especially when paid installs are expensive and attribution is incomplete. When 17 App Store installs cost about ¥750 apiece and sales are only $11, pause the broad campaign and turn those installs into conversations.
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