Miet-Akte

SonneAI

In-app purchases

About this app

Rental File — legally sound documentation of issues such as mold, dampness, defects, and ventilation. Tenant app: Document defects, solve tenant problems.

Whether it's a rented apartment, house, shared room, or individual room: What happens in your home is easily forgotten—and this is precisely what later leads to disputes. Rental File helps tenants keep a structured record of events: with dates, photos, deadlines, and exportable documents. No account required. Your data initially remains locally on your smartphone.

Many conflicts revolve around: How long has the mold been there? Was it reported in a timely manner? Was the apartment ventilated when humidity was high? Documenting this with dates and photos gives you a stronger position—when moving in, for rent reductions, or regarding utility costs.


Rental File ▸ WHEN THE APP HELPS

• Mold, high humidity, or dampness — damp walls, condensation on windows, mold in the bathroom, bedroom, or basement

• Defects and damage — leaky windows, broken heating, water damage, faulty electrical or plumbing systems

• Noise — parties, tradespeople, or persistent disturbance from neighbors (with optional noise level alerts via your phone's microphone)

• Move-in, move-out, and handover — meter readings, security deposit, handover protocol

• Rental costs — track base rent, utilities, and rent increases over time

▸ MOLD, HUMIDITY & VENTILATION — ROOM BY ROOM
Keep a mold diary for every room in your apartment: living room, kitchen, hallway, balcony. Photos show the progression over weeks and months. The ventilation log documents when and for how long you ventilated; optional weather data helps you understand humidity and dew point levels. This creates a traceable trail when it comes to moisture, mold, or your ventilation obligations.

For mold photos, you can optionally open MoldScan for an AI-powered initial assessment—not a diagnosis, but guidance for discussions with your landlord or a specialist company.

▸ DEFECTS, CORRESPONDENCE & NOISE
In the defect log, you record the category, severity, and status—windows, heating, water, electrical, mold, and more. This allows you to prepare defect reports: cover letter, deadline, proof of delivery. Letters, emails, and registered mail remain in one place—including responses from the landlord or property management company.

▸ DOCUMENTS, DEADLINES & RENT COSTS

• Store your lease, house rules, floor plan, and utility bill as documents

• Deadline Center: Set your own deadlines and those of your landlord — receive push notifications one day in advance

• Rent cost history showing base rent, utilities, and total rent over time

▸ PROOF & EXPORT
A hash chain protects the integrity of your entries on your device. You decide when to share information — with your landlord, tenants' association, or lawyer. JSON export is included free of charge. Evidence PDFs of the entire file, DIN-compliant letter PDFs, and email templates are available with Plus, Lifetime, or the Export Package per apartment.

▸ DATA PROTECTION — LOCAL FIRST
No login required, no advertising. Core data is stored locally (SQLite) on your device. Photos can be saved without EXIF ​​location data.

Privacy Policy: https://www.miet-akte.de/datenschutz/

▸ START FOR FREE — FREEMIUM
Free: one apartment, up to 60 entries, deadline push notifications, text copying, and JSON export. Sufficient for trying it out and for smaller tasks.

Optional paid features: PDF export, letter PDF, email sending, and unlimited entries — via Miet-Akte Plus (monthly/annual), Lifetime (€59 one-time fee), or Export Package per apartment (€14.99). No advertising. Details and prices in the app.

▸ IMPORTANT NOTICE
Miet-Akte is a documentation aid and guide — not legal advice, an expert opinion, or a substitute for a lawyer or expert. In case of imminent danger or serious mold infestation, consult a professional.

Guides, templates, and more at https://www.miet-akte.de/

Your digital apartment file — for tenants who want to be prepared for their apartment or house.

What’s new

Onboarding überarbeitet): Texte lesbar, scrollbare Einführung. Layout-Fixes beim ersten Start. Stabilität und Store-Vorbereitung. Local-first — Schimmel, Mängel, Lüftung, Fristen & Export wie gewohnt.