FirstSign helps founders check an early product idea before they spend a sprint on it. Paste a one-line idea and who it’s for; FirstSign returns target segments, realistic personas, and interview script.

From there, you get simulated interview transcripts, a summary of themes, likely risks and objections, and a compact action brief with positioning, success criteria, and concrete next steps. Re-run with different audiences, compare results side-by-side, and export the brief to share with your team so you can decide “build, tweak, or drop” with less guesswork.