Find.Identify.Save.
Grzybiarz is a mobile app for mushroom foragers. Its on-device AI helps you spot fruiting bodies in the leaf litter and suggests a species from a photo, and the app keeps a private map of your finds. Everything runs on your phone and works fully offline in the forest without signal.
The app is only an assistant for foragers. People decide what goes into the basket and onto the plate, based on judgement and experience, and with a mycologist’s help when something looks wrong. The app helps you build knowledge and does not replace it.
The app uses AI trained on Polish species. One model spots fruiting bodies in the frame, the other recognises the species from a photo. Both run locally without a network connection and report calibrated confidence, and when a result is uncertain, the app shows it as uncertain.
A segmentation model scans the camera image 15 to 30 times a second and outlines fruiting bodies, including those partly hidden in the leaves.
The classifier returns the most likely species with calibrated confidence. When the image is ambiguous, the app shows “I am not sure” instead of a guess.
The models are installed with the app. Recognition does not require sending the photo to a server and works even where there is no signal.
You move the camera across the leaf litter while the app scans the frame 15 to 30 times a second, draws a contour around each fruiting body and vibrates when it detects something worth a closer look. The YOLO model and the species classifier both run on the phone, with no network and no cloud.
Take a sharp photo of a single specimen. You get back the most likely species with calibrated confidence, a checklist of features to work through, and a list of toxic look-alikes. You always see why the app is sure, or why it is not.
Side-by-side comparisons of the most often confused pairs appear directly beside the recognition result: Boletus edulis and Rubroboletus satanas, parasol and death cap, wood mushroom and yellow-stainer. This way you decide deliberately and with the full picture.
Every confirmed find appears on your private map. Poland, Czechia and Slovakia come as downloadable offline packages, so the vector basemaps load with no signal. Finds stay on the phone until you mark them as public. The trip track goes to your account, where only you can see it, and you can turn the upload off in settings. You can also export the track to GPX.
Start a session as you head into the forest, let the GPS record your trail in the background, and stop it back at the car. The app records distance, steps, elevation gain and pace, and saves photos straight to your gallery. It works like Strava for mushroom pickers, but it has no tracking pixels and does not turn your trips into social media posts.
The atlas covers over 100 Central European species with descriptions, seasons and habitat tags. The cards are based on mycological literature, including the Wojewoda atlas. Each card lists the season, habitat, diagnostic features, field photos and toxic pairs.
Planning a trip starts with two questions: what is growing now, and whether there has been enough rain lately. The season calendar answers the first question: it shows every atlas species week by week, with season curves calculated from foragers’ observations. The conditions index answers the second: it uses rain and temperature from IMGW stations to assess whether the mycelium has what it needs to fruit, today and over the next five days.
You drag the hand around the year and see which species are coming into season, which are at their peak and which are ending. The curves come from Polish observations on iNaturalist and GBIF and the season limits from the atlas, so the calendar, the atlas and the game give the same dates.
The calendar pairs edible species with the poisonous look-alikes that are in season in the same week. The most dangerous pairs are at the top of the list, with a comparison of features and the number of weeks in which both species grow at the same time.
A score from 0 to 100 from the nearest station takes into account rain from 3 to 18 days ago, the average temperature of the week, frost and humidity. Every component is shown next to the score, and the strip for the coming days uses the weather forecast.
Once you mark a species with the bell, the phone reminds you when its season starts and two weeks before it ends. You can also turn on a Friday overview of the species at their peak and a notification about good conditions after rain.
The calendar shows when species grow, and the index shows whether the weather favours the mycelium. The app does not point to places and does not predict a flush of a particular species. The weather stations are in Poland.
The season calendar is also available on this site. The conditions index, watched species and notifications work in the app, where the calendar also works without signal.Start a trip and your phone draws your track on an offline map. You see where you have already walked, where you tagged each mushroom and how far you have come. This works without signal, because the basemap is stored on the phone.
Download a region once and the map then loads straight from storage. Even deep in a forest with no signal, you can see where you are.
GPS records your track as you walk. The app calculates distance, time and pace automatically, and you see the route on the contour map.
Every find appears on the map exactly where you picked it. A year later you can return to the same spot without guessing from memory.
After the trip you get distance, elevation and the list of finds. You can send the track as a GPX file or an image to anyone you like.
You download the vector maps of Poland, Czechia and Slovakia once, each country as a separate package. After that the basemap loads straight from your phone and works without signal, also in the Tatras and across the border.
The maps cover zoom levels 0 to 14 in the OpenMapTiles schema and are updated quarterly. You download only the countries where you forage. In Germany, Austria and Greece the map is streamed with no package to download, and the forest data for your area then stays on the phone.
Some outings end with an empty basket, and in some weeks nothing grows at all. In Forest Hunt virtual fruiting bodies appear in real woodland, matching the habitat and season, and you catch one by naming the species. This gives you something to collect and identify even when the forest floor is bare, including in the middle of the season.
The specimen appears at a real place in the forest. You walk to within a few dozen metres of it and identify it by its features, its habitat, or by which one of a pair must never be picked. You can make one mistake; after the second one the specimen disappears.
You plant spores from your hunts in three slots, and they grow with the kilometres of your trips. Nothing grows while you sit at home with the app open.
A virtual specimen joins your collection, but a confirmed find from the forest ranks above it. The app does not award points for picking or eating mushrooms and will not do so in the future.
Poland, Czechia and Slovakia come as offline map packages. In Germany, Austria and Greece the forest data for your area downloads automatically and stays on the phone.
The game runs in the mobile app, because spawns come from your real position in the field. There is nothing to launch on this page.Detection, recognition and the maps of downloaded countries work in the forest without a network. The app contains no tracking pixels.
Detection and classification run on your phone. A photo reaches the server only when you share it yourself: in a public find, as a training contribution or in the tester programme.
Trips are saved on the phone and in your account so they are not lost with the phone, and only you can see them. You can turn off the upload to your account in settings and export everything to GPX or to a trip backup file.
Grzybiarz is available on Google Play and the App Store. Species identification, the atlas and downloaded maps work in the forest without signal.
The app is available in Polish, English, Czech, Slovak and German.