I built an Android app that queries 5 AI models simultaneously and synthesizes their answers — BYOK, free to try

I've been building Sinth as a side project — an Android app that sends your question to Claude, ChatGPT, Gemini, DeepSeek, and Grok simultaneously, then generates a unified FUSION synthesis combining the best of all responses.

Why I built it: Each AI has blind spots. Claude reasons well, GPT is broad, Gemini is fast, DeepSeek is precise, Grok is blunt. Instead of choosing one, Sinth uses all five.

How it works:

BYOK (Bring Your Own API Keys) — no subscription, no middleman

All 5 AIs respond in parallel

Synthesis generated progressively as responses arrive

"Make it better" and "Redo with specific AI" buttons

Tech stack: React Native/Expo, Firebase Auth, Firestore, EAS Build

Cost to try: All 5 APIs have free tiers — zero cost to test Sinth.

Download (Android APK):

https://drive.google.com/file/d/1Tq-W2UnmLwoKcJo8UJGxOvwfi0ukXRGL/view?usp=sharing

Would love honest feedback from fellow builders — what works, what doesn't, what's missing.