SprkWrite your day, get mood colors. AI personas respond to your entries so journaling feels less alone
Live on App Store
Why I Started ThisAfter 3 months working on Lemonday (which combined Answer Book, Oblique Strategy, card collection and fortune telling), people who tested it couldn't easily understand the clear goal. I decided not to release it because it was too complicated. Learnings from Lemonday led me to simplify into Sprk - this time focusing only on encouraging people to write down life moments, but leveraging LLM to help people log life in text.
What Surprised MeThree things worked: First, right after each entry, Sprk categorizes the mood and presents it as a color palette. This visual attraction helps users understand themselves and creates short-term goals. Second, several predefined personas "see" each entry and sometimes leave short messages. People feel the diary experience isn't alone - there's always someone there to listen and respond, without worrying about privacy. Third, Sprk generates tailored writing prompts based on all your entries and mood analysis. But the generated prompts still have room to improve - sometimes repetitive even though I give it all context.
What This Opens UpHow can AI maintain prompt freshness while understanding deeper context? What's the right balance between AI insight and human interpretation in self-reflection tools?
Try It YourselfDownload on App Store • Watch your emotions become colors →