I got tired of spending 45 minutes reformatting the same idea for six different platforms. LinkedIn wants long-form, first-person takes. Instagram wants short, lowercase, vibes-first. Twitter wants punchy. They're completely different posts, but most people write one and paste it everywhere.
So I built a tool that handles the split automatically.
During onboarding, you paste 3-7 of your own posts. An LLM reads them and builds a persistent "voice profile", your vocabulary level, sentence style, tone, personality patterns. Every piece of content you generate after that is written in your voice, not some generic AI voice. LinkedIn posts come out sounding like you, not like a press release.
You write one prompt. It fans out to LinkedIn, Twitter/X, Instagram, Threads, Facebook, and newsletter simultaneously. Each one is natively formatted for that platform, different length, different structure, different energy. It also does a live web search before writing so the output is grounded in current trends, not stale training data.
Some things I learned building this solo:
Voice profiles are the moat. Anyone can call an LLM. Making the output actually sound like you across 6 platforms is the hard part and it gets better the more you use it.
Instagram and LinkedIn prompts need to be totally isolated. I had a bug where a "long-flowing technical" voice profile was producing LinkedIn-style structured posts on Instagram. Took a week to fix properly.