Meet Linevigil — Where the books and Kalshi disagree. Watch the gap

Sports

Linevigil

Where the books and Kalshi disagree. Watch the gap.

Every feature, from the first launch.

No account, no login, no cloud. Everything runs on your device and works fully offline — nothing in this post is hidden behind a wall.

What Linevigil does

Linevigil is a watchlist for the gap between sportsbook lines (DraftKings, FanDuel, BetMGM, Caesars) and prediction-market odds (Kalshi). When the two move in opposite directions, that gap is the only edge retail traders have. Linevigil surfaces it.

What's in v1:

— Game watchlist: tonight's NBA/NFL/MLB games. Per game, you log: sportsbook moneyline, Kalshi implied probability, your own perceived true probability. Linevigil computes the implied edge per side. — Movement journal: tap a game to log each line movement (book opened −110, moved to −125 by tipoff). Linevigil charts the path. — Library: 14 hand-written line-movement patterns ('public reverse', 'sharp move', 'steam play', 'air ball') with what each one signals. Drawn from public sports-betting reference materials. — No automated trading. No book integration. No real money. Linevigil is a journal.

Free.

A look inside

Tap any screenshot to open the full-resolution version.

What's inside

Game watchlist — Per-game book vs Kalshi vs your own.
Movement journal — Log line moves over time.
Pattern library — 14 line-movement patterns explained.

Why we built it

Per Trade Ideas Apr 2026: 87-90% of Kalshi volume is sports; Robinhood drives >50% of Kalshi notional. Sportsbooks vs Kalshi pricing diverge constantly. Most retail bettors don't track the gap.

What makes it different

Linevigil is the only iOS app whose surface IS the sportsbook-vs-Kalshi spread. Not a sportsbook (no real bets). Not Kalshi (no order entry). It's the discipline journal across both.

Who it's for

Players who want to play, not configure — minimal setup, maximum time on the thing you love.

In one line: Where the books and Kalshi disagree. Watch the gap.

Try it

See the Linevigil app page for the full feature list, the info table, and support links.

Use Linevigil, found a bug, or have a feature request? Comments are open below — anonymous is fine.