App Masters · 2026-09-26
Cal AI’s Co-Founder Shares His App Growth Secrets
App Masters livestream with Jake Castillo, co-founder of Cal AI (acquired by MyFitnessPal). He explains the influencer playbook inherited from Umax: signing health and fitness creators without brand deals, letting them keep their normal formats, paying a base rate for four cross-posted videos with view bonuses capped at 1M, pricing by CPM below RPM, picking creators by worst-case average views, 20+ outreach accounts, an automated creator-ops tool, UGC accounts, and when to add paid ads. Host ends with short solo app audits.
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Numbers mentioned
| Who | Metric | Value | Context | When |
|---|---|---|---|---|
| Cal AI | time to milestone | 15 months approximate | Start to sale to MyFitnessPal | 2:17 |
| Cal AI | count | 300 influencers approximate | Influencers managed at once (300-plus) | 4:13 |
| Cal AI | count | 20 accounts approximate | Extra Cal AI social accounts created for creator outreach, one per outreach specialist | 27:37 |
| Cal AI | activity volume | hundreds approximate | 27:37 | |
| Cal AI | creator pay | USD 400per 4-post deal approximate | Example influencer deal: $400 for four posts, cross-posted to TikTok and Instagram | 13:04 |
| Cal AI | creator pay | USD 350–450per 4-post deal approximate | Influencer base rate for four posts, before view bonuses | 16:24 |
| Cal AI | views | 1M viewsper video approximate | View count at which influencer view bonuses stop (cap) | 17:51 |
| Cal AI | count | 20–30 seconds approximate | Best point in an influencer video to bring in the app without hurting views | 10:10 |
| Cal AI | downloads | 0 downloads/day approximate | Early days: downloads on days with no influencer video going live | 22:14 |
| Cal AI | downloads | 100 downloadsper hour illustrative | Later baseline; spiked to about 200/hour when a creator video went live | 22:14 |
| Cal AI | count | millions approximate | Creator videos posted for Cal AI to date | 21:41 |
| Cal AI | views | 25K viewsper video | Minimum average views per video for an influencer to be signed; sweet spot 25K-1M | 37:04 |
| Cal AI | views | 25K–1M viewsper video approximate | Sweet-spot creator range for cult-like, high-converting audiences | 37:51 |
| benchmarkViews a typical new UGC account video gets | views | 500–1,000 viewsper video approximate | 30:51 | |
| benchmarkSuggested UGC creator base pay (guest's recommendation) | creator pay | USD 25–30per video illustrative | Paid for every video, about $600/month, plus a view bonus | 30:51 |
| benchmarkEffective CPM of a UGC creator deal when one video a month hits ~1M+ views | cpm | USD 1.5–2 illustrative | $600/month base with one 1M-view video = $2 CPM; ~$1,000 incl. bonus for ~1.5M views = ~$1.50 | 30:51 |
| aggregateShort-form performance gap between TikTok and Instagram across apps the guest knows | growth rate | 1.2 x estimate | Some apps do ~1.2x better on TikTok, others ~1.2x better on Instagram | 24:08 |
| benchmarkDownloads per 1,000 views an app should hope for from organic content | conversion rate | 3–7 downloads per 1,000 views approximate | views -> download, organic creator content | 45:11 |
| benchmarkShare of downloads that should reach the paywall | conversion rate | 75% approximate | download -> paywall view, minimum target | 45:25 |
| benchmarkPaywall to subscription conversion to aim for | conversion rate | 10% approximate | paywall view -> subscribe, minimum target | 45:25 |
| benchmarkiOS ATT prompt opt-in rate (host's rule of thumb) | conversion rate | 50–60% approximate | Users who accept the ATT prompt | 54:28 |