Jens Korinth

About me

I am a software developer currently located in the city Frankfurt am Main, Germany. After I finished my media computer science studies in '07 I've been working for a software and consulting company here in Frankfurt for almost six years. My continued interest in computer science in general, compiler construction, language and hardware design in special have led me to pursue a Ph.D. in computer science. This highly rewarding journey is still in progress.

Scientific interests

  • Heterogenuous Parallel Computing, FPGAs
  • High-Level Synthesis
  • Hardware Design with Hardware Construction Languages (Chisel)
  • Compiler Construction, Optimizing Compilers, Language Design

Favorite Programming Languages

  • Haskell (mostly due to the sheer beauty of the language design)
  • Scala (best of many worlds)
  • C (really!)
  • Objective-C, C#

Personal Interests

  • Music of all kinds and sorts
  • Electronics, Embedded Systems
  • Formal Methods: Finite Transition Systems, Process Semantics


The iOS app »GuitarScales« is an app for guitarists that shows many different guitar scales with arbitrary base notes on the guitar neck. It displays the scale as positions on the neck, the names of the respective notes and highlights the base notes to ease learning of a new scale/base.

You can also define your tuning, for instance show the scale in Drop D or an open tuning. It also allows you to define your own custom scale, just by tapping in the notes on the neck.

The free version of the app contains ads but a cheap ads-free version is also available.


  • Universal App for iPad & iPhone/iPod touch using full iPad & iPhone 5 screen!
  • easy to use interface that allows zooming in and out of any position on the neck
  • supports many scales including major, minor, pentatonic scales (major, minor, blues) and church modes
  • allows to define a completely custom scale, which may also be transposed!
  • support for different tunings, including open tunings
  • FREE version with ads!


Free version (Advertisments)

Full version (no Advertisements)



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Version 3.0 is out!

  • completely redesigned user interface!
  • iOS 7 look
  • smooth animations and bling-bling! ;-)
  • two minimalist color themes: white / black

Version 2.12 is out!

  • support for iOS 6, iPhone 5 and iPad Mini!


Stuck on a tough Sudoku? Ever been unable to solve a Sudoku, or been wondering whether there is a solution at all? Or maybe always wanted to impress buddies or coworkers by solving an almost impossible Sudoku?

Here's your solution! einkaufen will solve any solvable Sudoku within seconds. If you want to solve it yourself, you can also get hints!

The basic idea for this app was to solve Sudoku using a general first-order logic solver and see if it works on the iPhone. The latest version of this app is now free, thanks to iAds.


  • solves Sudokus of any difficulty
  • fast input method: dial-in the numbers
  • multi-level hint system: show valid values at empty fields, highlight fields with only one or no possible value, show correctness of each guess
  • iPhone 5, iPad, iPad Mini support
  • FREE version with iAds!




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Version 2.3

  • new version for iOS 7!
  • support for 64bit!
  • improved user interface
  • game is saved automatically
  • several minor improvements & bugfixes

Version 2.2 is out!

  • new feature: get a new sudoku challenge by shaking!
  • generates random sudokus (casual difficulty)
  • improvement: app now asks before erasing your solution (restart button)
  • minor improvements & clarifications in localization

Version 2.1 is out!

  • bugfix: fixed a stupid bug in the field hints

Version 2.0 is out!

  • iPhone 5 support
  • Now UNIVERSAL - iPad & iPad Mini are now supported
  • Completely re-designed UI
  • New hint system: You can now activate different hint levels to get help with the Sudoku, without getting the full solution immediately.


einkaufen is a no-nonsense, minimalistic shopping list. Add items to your list, group them into colored categories and tick them off with a single touch during shopping. Ever ran back through the entire store because you forgot something in the groceries section? E.g., the zucchini that your current list app moved to the very end of the list? That's why in einkaufen your items are grouped by categories; just set them up to match their location on your favorite shopping tour and you'll never have to turn around again to collect that missing item. Need to quickly find a specific item? Just switch to alphabetic ordering with a single touch. And, saving the best for last: einkaufen is free.

Short User Guide

Upon first launch, einkaufen will populate your list with demo items and categories. You can delete or modify them at will, as shown in the following.

Switch between categorical and alphabetical ordering

Tap the button in the top right corner to switch between orderings: You can switch between categorical ordering (items are ordered by categories and alphabetical within the category) and alphabetical ordering.

Move between lists

There are two lists in **einkaufen**: The current shopping list 'Shopping' and the ticked off list 'Done'. You can switch between them by swiping left or right on the title at the top.

Move items between lists

To move an item to the other list, simply tap it once and it will disappear. Switch to the other list and tap it again to move it back.

Edit and delete items

Simply swipe left on an item to edit. To change the item category, tap the colored box on the left. This will open the category selection view: On the top, you'll see the name of the item you're categorizing. Tap on any category to select it. To delete the item simply tap the button with the trashcan on the right-hand side.

Add items

Tap on the '+' at the bottom of the 'Shopping' list to add a new item. It will insert a new randomly named item that you can edit directly (see [Editing and deleting items]).

Edit and delete categories

When in category selection, you can edit the categories exactly like items: Just swipe left on the category you want to edit. Tap on the colored box on the left-hand side to select a color. Tap the trashcan button on the right to delete the category. Note: You can only delete empty categories.

Reorder categories

Categories can be reordered by dragging the item in the list using the move handle on the right-hand side (when not in edit mode). Just touch down on the handle, move the category anywhere you'd like in the list, and release. The 'Shopping' list in grouped mode will reflect this ordering immediately.

Backup of your list

A backup of your list is automatically included in your iTunes backups. You can also extract and restore the database via iTunes file sharing.




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Version 1.0

  • compatible with all iOS devices
  • free version with advertisements