Gljivar — a mushroom forecast app and foraging guide
Gljivar shows where and when it pays to go into the forest. Every day the model weighs the rain and temperature of the past weeks against the time of year and the climate zone, and gives every 10 km cell of the map a score from 0 to 100, for today and the next seven days. Gljivar is the studio's own app, from the idea and a check against real data to publishing on Google Play and Apple's App Store.
Before writing a line of code I checked whether the idea holds up: I tested the model on more than 17,000 real finds of porcini, chanterelles, parasols and morels, mostly from Austria, Switzerland and southern Germany. The rain signal is real: porcini are found most often 10 to 30 days after rain, chanterelles after only a few days. The forecast is built on that.
- A forecast map for 9 countries: Croatia, Slovenia, Italy, Austria, Germany, Switzerland, Serbia, Bosnia and Herzegovina and Hungary, for four groups: porcini, chanterelles, parasols and morels
- Eight days, including today: a score for today and each of the next seven days, on a scale from poor to excellent
- Rain layer: an estimate of how much rain fell in the last 7 or 14 days
- My spots: save your spots and the app tells you when their forecast rises
- A guide to 222 species: photos, season, habitat and the look-alikes. Gljivar does not identify mushrooms and never judges edibility
- Picking rules: daily limits, minimum size, protected species and permits for all nine countries, plus the poison control number
- Six languages, works offline: Croatian, Slovenian, English, Italian, German and Hungarian. No account, and your location never reaches our server
- Free app: with ads, which can be removed for a year or for good. Since its launch in September 2026 it has been downloaded more than 2,500 times in 27 countries, most of all in Croatia and Slovenia, then Italy, Germany, Bosnia and Herzegovina, Switzerland, Austria and Serbia
I ran the whole cycle: research and testing the model on real finds, the daily forecast computed from climate data, the interface and map design, the guide to 222 species and the picking rules for nine countries in six languages, the icon, store screenshots and texts for both stores, and publishing on Google Play and the App Store.
Technology: forecast — Python, a daily automated run on ERA5-Land and ERA5 reanalysis (Copernicus/ECMWF) and DWD ICON-EU and ECMWF forecasts. Android — Kotlin and Jetpack Compose with Google Maps. iOS — Swift, SwiftUI and MapKit. Both apps have alerts for saved spots, in-app purchases and ads with GDPR consent.
Download on the App Store (iOS) Get it on Google Play (Android)
