Point your phone at the sky. Helios overlays where the sun will be — today, in winter, all year — onto whatever your camera sees. Map shade from trees and buildings. Get a month-by-month solar yield report for your site. All on-device, no servers.
Built for homeowners weighing rooftop solar and for installers who want a quick on-site shade audit. No spreadsheets, no satellite data, no cloud — just your camera, your sky, your report.
Today's arc, summer and winter solstice extremes, and the moon's nightly journey — all overlaid live on what your camera sees.
Pan across the sky and Helios builds a map of trees, buildings, and terrain. Obstructed segments of the sun's path turn red.
Clear-sky kWh/m² estimate for every month, with shade loss broken out. Adjust panel tilt and facing with sliders and watch it update live.
Share the report as a one-page PDF for proposals, or a portrait image for messaging. Installers, this is for you.
Every scan saves automatically, keyed by location. Name them, revisit anytime, compare reports across properties. Free tier keeps your 3 most-recent sites unlocked; Pro unlocks unlimited for installers and serious planners.
Everything stays on your device. No accounts. No analytics. No first-party tracking. Free tier saves your 3 most-recent sites and shows one banner ad on the report screen; Pro unlocks unlimited sites and removes ads.
From install to a printable yield report in about five minutes. No sign-up, no setup, no spreadsheets.
Open Helios outside and aim your phone at the sky. The sun's arc snaps into place over the camera view. Pan around — the overlay tracks the world as you move.
Slowly sweep the camera across the directions the sun travels. Trees and buildings get mapped automatically. Segments of the sun's path they block turn red. Aim for ~80% coverage — you'll see a "Site mapped!" message when you're there.
Tap the gear → View solar report. See the annual yield in kWh/m², a month-by-month breakdown, and a chart of clear yield vs. shade loss. Slide the tilt and facing sliders to compare panel orientations. Export as PDF or image.
Pro unlocks unlimited saved sites (free tier keeps your 3 most-recently-scanned) and removes the single banner ad on the solar report screen. No subscription, no recurring charges. Everything else in Helios stays free for everyone, forever. Final price varies slightly by country — Google auto-converts to your local currency and applies any local VAT.
Get Helios for AndroidHelios has no servers. No accounts. No analytics. No first-party trackers. Your camera frames, your GPS location, your scans — all of it lives in your device's local storage and goes nowhere else.
Android 7 (Nougat) or later. Needs Camera and Location permissions — granted at launch, never sent anywhere. The whole app is about 25 MB.