Christian Kempf

Projects from Bisingen, Germany

Built from practice, for practice.

Apps and devices for the boat, the apiary, the garden, the family and the home network. They need no manufacturer account and don’t keep track of who uses them.

LOGisch

By a skipper, for skippers

The logbook that writes itself.

The digital logbook for sailors: automatic entries, mileage certificates as PDF, anchor watch, marine weather and AIS, optionally with values from the boat instruments via the LOGisch gateway. Offline, no account, no cloud.

  • for Android
  • works offline
  • PDF & GPX
Go to LOGisch

BienenWaagenManagerHive scale & app

Hive scale + beekeeping app

Your colonies. Always in view.

The self-powered hive scale transmits via LoRaWAN, Wi-Fi or 4G. Its app shows nectar flow, feeding needs and swarm alarms, and keeps your hive records, by NFC tag and voice.

  • LoRaWAN · Wi-Fi · 4G
  • Free firmware & build guide
  • Hive records via NFC & voice
Go to BienenWaagenManager

RudelPlan

Rudel app · Family calendar

The whole family. Column by column.

Every family member’s events side by side, straight from the calendars on the phone. Shared events in the pack calendar – encrypted via your own OneDrive, without a server of its own.

  • for Android
  • in development
  • end-to-end encrypted
Go to RudelPlan

RudelKey

Rudel app · Passwords

One key. For every password.

The password manager that fills in apps and browsers, creates strong passwords and opens with your fingerprint – on the phone and on the Windows PC with Firefox. Shared vaults for the family, encrypted in your own cloud folder.

  • for Android and Windows
  • in development
  • no provider account
Go to RudelKey

RudelSafe

Rudel app · Documents

The family’s documents. Kept safe.

Scan ID cards, insurance policies and contracts with the camera, find them again by full text and get reminded of deadlines – encrypted in your own OneDrive or Nextcloud, with shared safes and an emergency folder for the family.

  • for Android
  • in development
  • end-to-end encrypted
Go to RudelSafe

RudelOrga

Rudel app · Group & club

Plan together. Without chat chaos.

Lists, polls and scheduling, a group kitty, helper lists and inventory with lending – for family, friends, flatmates or a club. Synced encrypted via your own OneDrive or Nextcloud folder.

  • for Android
  • in development
  • end-to-end encrypted
Go to RudelOrga

RudelCash

Rudel app · Club events

Ordered, printed, paid.

Ordering and checkout for club events: service phones on the Wi-Fi, tickets for bar and kitchen – on network, USB or Bluetooth printers –, tabs instead of rigid tables, NFC tables and card terminal – with no internet at all.

  • for Android
  • in development
  • no internet needed
Go to RudelCash

RudelRally

Rudel app · Rally & orienteering

On average. To the second.

Average calculator, tripmaster, time controls and orienteering solver for rallies, orienteering drives and regularity tests – distance by GPS, OBD-II or wheel sensor, large in-car display, watch app, follow-me for the family and a competition mode without map.

  • for Android
  • in development
  • OBD-II and wheel sensor
Go to RudelRally

Parzello

Garden, field & woodland

Your land. On the aerial photo.

Map plots and plants on the official aerial photo, plan crops and rotation, record harvests and work – from the raised bed to the orchard. Offline, no account, no cloud.

  • for Android
  • works offline
  • NFC tags
Go to Parzello

TonStrom

Sound for the whole house

Your phone’s sound. On every speaker.

Whatever plays on your phone, to network speakers, receivers and TVs on your Wi-Fi – in party mode to several at once, in sync. No cloud, no account.

  • for Android
  • in development
  • your own Wi-Fi only
Go to TonStrom