I built the Vivino of coffee to track and rate my beans, log my brew experiments and discover new roasters. Turns out there are quite a lot of specialty coffee nerds like me.
1,100
Downloads
5.0★
Avg rating
Built with
AntigravitySwiftReplit
✨ AI Feature
Snap a bag, Gemini fills in the coffee sheet, Photoroom removes the background and relights the picture.
Platform
iOS · Web
500k
Reddit views
I built the Vivino of coffee to track and rate my beans, log my brew experiments and discover new roasters. Turns out there are quite a lot of specialty coffee nerds like me.
1,100
Downloads
5.0★
Avg rating
Built with
AntigravitySwiftReplit
✨ AI Feature
Snap a bag, Gemini fills in the coffee sheet, Photoroom removes the background and relights the picture.
While training in the hills of Lausanne for a 10K race, I kept asking myself: what's the smartest way to adjust my pace on the climbs? So I built a tool that reads the race map, spots the steep gradients, lets you set your goal time and strategy (negative split, even effort, etc.), and hands you a segment-by-segment pacing plan to follow on race day.
12k
Strategies in week 1
💚 Cheering map
My partner suggested it: a cheering map so friends and family know exactly where and when to show up and cheer you on.
17k
Reel views
Built with
Replit
📊 Analytics
≥67%
of visitors generated a pacing strategy
While training in the hills of Lausanne for a 10K race, I kept asking myself: what's the smartest way to adjust my pace on the climbs? So I built a tool that reads the race map, spots the steep gradients, lets you set your goal time and strategy (negative split, even effort, etc.), and hands you a segment-by-segment pacing plan to follow on race day.
12k
Strategies in week 1
💚 Cheering map
My partner suggested it: a cheering map so friends and family know exactly where and when to show up and cheer you on.
17k
Reel views
Built with
Replit
Beta test
Now with voice
#3
Cocast
Daily AI byte-sized podcasts generated for your interests
Tell Cocast what you're curious about and get byte-sized AI-generated podcasts every morning. The latest prototype swaps a ten-topic tap grid for a short voice conversation: you talk, the orb listens, and your interests land as cards on screen.
What the prototype taught me
1
Talking beats tapping. A short conversation captures far richer context about why you care than a grid of topics ever did.
2
Show the listening. Visible progress, interest cards and clear orb turn states keep a voice-only flow from feeling like talking to the void.
3
Keep the agent on a leash. Its whole power over the product is five functions, which keeps it predictable.
4
About $0.37 a session. Roughly four minutes on average: $0.33 voice platform, $0.04 model.
Costs measured on prototype test sessions, not production, and not a guarantee.
Tap play — it's a real episode
YC1 MAY·5 min
Beyond the Chatbot: Flying the AI Spaceship
0:00 / 0:00
New sample, straight from the feed
AI13 NOV·1:11
AI’s Margin Problem: The Inference Cost Crunch
0:00 / 0:00
Another fresh sample
HI13 NOV·1:03
Weaponized Stone: The Dark Secret of Paris
0:00 / 0:00
Voice-first onboarding
An ElevenLabs voice agent interviews you about your interests. It can only act through five functions, and every save shows up as a card while the orb signals whose turn it is.
Tell Cocast what you're curious about and get byte-sized AI-generated podcasts every morning. The latest prototype swaps a ten-topic tap grid for a short voice conversation: you talk, the orb listens, and your interests land as cards on screen.
What the prototype taught me
1
Talking beats tapping. A short conversation captures far richer context about why you care than a grid of topics ever did.
2
Show the listening. Visible progress, interest cards and clear orb turn states keep a voice-only flow from feeling like talking to the void.
3
Keep the agent on a leash. Its whole power over the product is five functions, which keeps it predictable.
4
About $0.37 a session. Roughly four minutes on average: $0.33 voice platform, $0.04 model.
Costs measured on prototype test sessions, not production, and not a guarantee.
Tap play — it's a real episode
YC1 MAY·5 min
Beyond the Chatbot: Flying the AI Spaceship
0:00 / 0:00
New sample, straight from the feed
AI13 NOV·1:11
AI’s Margin Problem: The Inference Cost Crunch
0:00 / 0:00
Another fresh sample
HI13 NOV·1:03
Weaponized Stone: The Dark Secret of Paris
0:00 / 0:00
Voice-first onboarding
An ElevenLabs voice agent interviews you about your interests. It can only act through five functions, and every save shows up as a card while the orb signals whose turn it is.
A private app for our household, tailored to our specific needs — replacing 3-4 different apps on our phone, from a personalised cookbook to a Pinterest-style 2026 activities wishlist.
Platform
Web · PWA
✨ AI Feature
Centralising every document in our home — from the washing-machine manual to our insurance contracts — to power a hyper-contextualised AI chatbot.
Built with
ReplitPWA
A private app for our household, tailored to our specific needs — replacing 3-4 different apps on our phone, from a personalised cookbook to a Pinterest-style 2026 activities wishlist.
Platform
Web · PWA
✨ AI Feature
Centralising every document in our home — from the washing-machine manual to our insurance contracts — to power a hyper-contextualised AI chatbot.
I built an app to control my espresso machine via WiFi websocket, including turning it on, setting the brew temperature and steam wand pressure. The app can also display the machine's live telemetry and beautiful charts throughout the shot.
14
Daily active users
Platform
iOS
Built with
AntigravitySwift
⚖️ Brew-by-weight
The app launches a brew, controls the pressure profile during the shot and predicts when to stop based on a smart algorithm — using the live weight from the Bluetooth-connected scales to hit your target g output.
I built an app to control my espresso machine via WiFi websocket, including turning it on, setting the brew temperature and steam wand pressure. The app can also display the machine's live telemetry and beautiful charts throughout the shot.
14
Daily active users
Platform
iOS
Built with
AntigravitySwift
⚖️ Brew-by-weight
The app launches a brew, controls the pressure profile during the shot and predicts when to stop based on a smart algorithm — using the live weight from the Bluetooth-connected scales to hit your target g output.
Prototype
Retro vibes 📼
#6
The Brainstorm
Private AI transcription & brainstorm personas
I often go for a walk after lunch 🚶 and it's a time to think. I sometimes use Gemini's live voice mode, or Monologue for transcriptions, but the former gets interrupted (or interrupts me) too often and crashes on longer conversations, and the latter feels like I'm talking to the void. I wanted an app where I could press record, talk for a while, and then ask the AI to help me go further on my train of thought — with different personas available depending on what I need.
🎛️ Design
Inspired by the Sony Walkman from my childhood — the whole app leans into a full retro cassette-deck aesthetic.
✨ AI Feature
I'd love to run transcription, the personas and TTS fully on-device — but Apple Intelligence's local models didn't quite cut it. Currently exploring other on-device model options.
Built with
AntigravitySwiftWhisperGemini
Platform
iOS
I often go for a walk after lunch 🚶 and it's a time to think. I sometimes use Gemini's live voice mode, or Monologue for transcriptions, but the former gets interrupted (or interrupts me) too often and crashes on longer conversations, and the latter feels like I'm talking to the void. I wanted an app where I could press record, talk for a while, and then ask the AI to help me go further on my train of thought — with different personas available depending on what I need.
🎛️ Design
Inspired by the Sony Walkman from my childhood — the whole app leans into a full retro cassette-deck aesthetic.
✨ AI Feature
I'd love to run transcription, the personas and TTS fully on-device — but Apple Intelligence's local models didn't quite cut it. Currently exploring other on-device model options.
Built with
AntigravitySwiftWhisperGemini
Platform
iOS
Field notesBlog
Long-form write-ups of what worked, what broke and what it cost.
How Cocast replaced a ten-topic tap grid with a voice agent: the orb and its turn states, the five functions the agent is allowed to call, the transcripts, the tuning, and what a four-minute prototype session actually cost.