Fish Tech: a free fly fishing app for live water and smart flies.

Fish Tech is a fly fishing app built because checking five tabs before every trip — USGS, weather, the fly shop blog, the solunar calendar, the state stocking report — is a terrible way to plan a day on the water.

What we do

We pull live USGS streamflow, gauge height, and water temperature for thousands of rivers across the U.S., overlay solunar feeding windows, and translate it all into plain-English fly recommendations and "go now / wait" calls. Every river page shows the same numbers a guide checks at 5 a.m., already interpreted.

Who we are

Fish Tech is built by a small team of fly anglers and engineers who fish the Mountain West and the Driftless. We're not a content farm — every guide, fly rec, and seasonal window on this site reflects how we actually plan trips.

How it's free

The core map, river data, and flow alerts are free forever. Pro features (AI trip optimizer, voice catch logging, advanced strike-zone analysis) fund the data pipeline. No ads, no selling your fishing spots.

Read more

• The Best Fly Fishing App in 2025 — what to look for, and how the major apps compare.
• Best Fishing Apps in 2025 (Honest Roundup) — a fly angler's review of Fishbrain, TroutRoutes, Navionics, and more.
• How to Read USGS Streamflow for Fly Fishing — the four numbers that decide whether today is worth driving to the river.