Peeko Prose is a fiction checking tool that highlights potential issues in a writer's work without making automatic changes or offering generic improvements. The tool is designed to draw attention to areas that may need a second look, while leaving all creative decisions to the writer. It does not rewrite sentences or replace any part of the original text. Instead, Peeko Prose identifies possible concerns, explains them in plain language, and allows the writer to decide how to proceed. The tool separates recognisable dialogue, direct thoughts, and time cues before evaluating tense, and its language remains cautious to account for rhythm, voice, and narrative intent. Peeko Prose runs locally in the browser and can be installed for offline use. Imports, drafts, and reports remain on the user's device and are not attached to any account. The tool stores only a fingerprint and a short identifying cue for each choice on the device, not the full manuscript. Users can see exactly what is stored and how to move or recover that data between browsers. Typical use involves pasting fiction into the tool, after which Peeko Prose scans the text and returns observations about possible concerns. Users can adjust individual checks to suit their style, choose from preset sensitivity levels, or create a custom preset. Features include adjustable repetition distance, sentence length flags, comma density flags, and adverb handling (adverbs are never treated as automatic errors). Punctuation and tense checks are available in every preset. The tool checks spelling conventions only and does not rewrite words automatically. Peeko Prose is free to use, with optional support for continued development available through Ko-fi. It is accessible as a web application and can be installed via the browser menu for quick, distraction-free, and offline checking. The tool is currently in beta, and users are invited to provide feedback on what worked, what felt inaccurate, and what the tool may have missed. No draft content is attached automatically when providing feedback.