Castify
The original viral AI podcast app.
Turn anything into a podcast.
0+ downloads·Doubled conversion·0+ countries·0M+ views
View case study →AVAILABLE FOR PROJECTSAVAILABLE FOR SELECT PROJECTS · Q2 2026
N. Sullivan / Vol. 01 / 2026
I buildAI iOS appsthat ship andmake money.
Castify downloads
70,000+
Paid conversion
2×
up from 5.4%
Revenue per install
2×
year over year
Lifetime revenue
$80K+
bootstrapped & solo
Production AI iOS apps end-to-end — from architecture to App Store launch. Available for a small number of projects per quarter.
SELECTED WORK
Padsnap
AI real estate photography for property managers. Built the iOS app for the founding team.
Live · Generating revenue
WHAT I BUILD
AI iOS App Build
Starting at $15,000
6 to 12 weeks. From concept to App Store, end-to-end. AI integration, subscription paywall, ASO, and launch — all handled by the same person who built Castify.
Inquire →AI Integration Audit
Starting at $5,000
2 to 3 weeks. I audit your AI stack — providers, architecture, costs — and deliver a written report with recommendations and a cost-reduction roadmap. Past audits have surfaced 5–20× savings opportunities.
Inquire →Fractional AI Engineer
Starting at $8,000/month
10 to 15 hours per week, 3-month minimum. Embedded with your team as the senior AI engineer who can also ship product. For founders who need a co-pilot, not a contractor.
Inquire →ABOUT
Filed a provisional patent on Castify's underlying technology in 2023, while still in college. Spent the next year building it solo - no co-founder, no revenue, no real signal anything would work. In December 2024, a single piece of content reached 17 million views over the course of a week. I quit my banking job the following week.
Sixteen months later: 70,000+ downloads, $80,000+ in revenue, paying users in 50+ countries - all built and operated alone, with every dollar going back into the business.
Before Castify, I came out of UMass Amherst with a double major in Psychology and Computer Science (graduated a semester early). My day job was at PeoplesBank, where I owned SQL analytics and reporting on $1B+ in uninsured deposits during the bank's exit from DIF insurance - the kind of institutional-grade data work that's now the backbone of every strategic decision I make at Castify.
I think like an operator because I was one. Now I help other founders ship AI products that actually make money.
CONTACT
Have a project in mind? The fastest way to start is email - I read everything and reply within 48 hours.
Email me at nate@natesullivan.ai.
Currently taking on 1–2 new projects per quarter.
natesullivan.ai© 2026 Castify LLC