I need a small, German-language Android app that lets the crew at our Skigebiet log their shifts and grooming work in a clean, structured way. We are only ten people, so a lightweight email-and-password login is enough; no social logins or open access. Hauptseite – Arbeitszeit • Each user starts and stops a timer or enters start/stop times manually. • I must be able to pull weekly and monthly summaries per user and for the whole team, then export those reports as CSV straight from the device. Zweite Seite – Präparierte Loipen After clocking out, the user chooses the routes they just prepared. The fixed list must appear exactly like this: – Loipe Säätliboden (Rüti GL) – Nidfurn – Leuggelbach – Rundkurs Leuggelbach – Schwanden - Nidfurn – Schwanden – Luchsingen - Hätzingen (Skistübli) – Hätzingen – Linthal Dritte Seite – Spesenbelege Option to snap a photo or pick an image/PDF of a receipt incurred during the shift and upload it so I can download everything later. Weitere Anforderungen • Clear German UI texts; no mixed languages. • Works on current Android versions, offline capable for bad mountain reception, and syncs when back online. • Simple admin view (can be in-app or browser) to create/edit the ten user accounts, reset passwords, and download the CSV reports and uploaded receipts. • Source code and installable APK are the final deliverables; please include a short read-me so I can rebuild if needed. If you can build this with a familiar stack such as Kotlin + Room/WorkManager or Flutter + Firebase, great—just keep the setup straightforward and documented.