Fossy Protokoll
Document rental defects and build protocols — offline, no tracking.
Version: 0.5.1
Added: 27-09-2026
Updated: 27-09-2026
Added: 27-09-2026
Updated: 27-09-2026
Fossy Protokoll helps tenants in Germany keep a verifiable record of defects in
their flat: noise disturbance, mould, heating failures and more.
From the recorded occurrences it builds a protocol covering a chosen period, and
a factual defect notification addressed to the landlord. Both can be saved and
shared as PDF or Markdown.
Note: the app is in German
The interface and all generated documents are written in German, because they
follow German residential tenancy practice.
Not legal advice
The app documents, it does not advise. The generated texts cite no statutes,
claim no rent reduction and set no deadline of their own. A response date only
appears when you enter one yourself.
Everything stays on the device
Data lives in a local database, photos in the app's private directory. The app
requests no permission that touches your data or the device, never accesses
the network, and contains no
tracking or analytics. When you export something, you choose the destination
yourself.
Android's automatic backup is switched off as well, so your defects and photos
never reach a cloud account. Instead you can create a full backup as a ZIP file
at any time and restore it later, for instance when moving to a new phone.
Without such a backup the data is lost if the device is.
Features
* Manage tenant profile, rental units and landlords
* Record defects by category: noise, mould, heating, hot water, damp, sanitary,
electrics, windows and doors, pests, other
* Document individual occurrences with period, category, affected room,
severity, impact, witnesses and notes
* Attach photos to defects and to individual occurrences, with captions
* Assemble protocols over a period and refresh them later
* Generate a defect notification for the landlord
* Export as PDF with embedded photos, or as Markdown
* Full backup and restore as a ZIP file
Free and open source
The source code is available under GPL-3.0-or-later. The app uses no proprietary
libraries.
their flat: noise disturbance, mould, heating failures and more.
From the recorded occurrences it builds a protocol covering a chosen period, and
a factual defect notification addressed to the landlord. Both can be saved and
shared as PDF or Markdown.
Note: the app is in German
The interface and all generated documents are written in German, because they
follow German residential tenancy practice.
Not legal advice
The app documents, it does not advise. The generated texts cite no statutes,
claim no rent reduction and set no deadline of their own. A response date only
appears when you enter one yourself.
Everything stays on the device
Data lives in a local database, photos in the app's private directory. The app
requests no permission that touches your data or the device, never accesses
the network, and contains no
tracking or analytics. When you export something, you choose the destination
yourself.
Android's automatic backup is switched off as well, so your defects and photos
never reach a cloud account. Instead you can create a full backup as a ZIP file
at any time and restore it later, for instance when moving to a new phone.
Without such a backup the data is lost if the device is.
Features
* Manage tenant profile, rental units and landlords
* Record defects by category: noise, mould, heating, hot water, damp, sanitary,
electrics, windows and doors, pests, other
* Document individual occurrences with period, category, affected room,
severity, impact, witnesses and notes
* Attach photos to defects and to individual occurrences, with captions
* Assemble protocols over a period and refresh them later
* Generate a defect notification for the landlord
* Export as PDF with embedded photos, or as Markdown
* Full backup and restore as a ZIP file
Free and open source
The source code is available under GPL-3.0-or-later. The app uses no proprietary
libraries.