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Linux & C++

Prepaid balance widget

This is an app that parses the current prepaid balance from my provider's website. It also roughly shows the amount of data used of my 1GB data volume. It can also load my balance with €15,- via a simple click. It updates automatically every day.

APAC alias "HsH App"

This app unites many services of the University of Applied Sciences and Arts in Hannover. With almost 3000 users (end of 2015) it was so successfull that it became the official University app in 2014. I maintained it for two years. Then I gave it to the AStA (Student Committee) and they will continue to maintain it. This is my legacy to the University :-)

This app helps to keep track of a lot of information like all the books borrowed at the Library of the University of Applied Sciences and Arts in Hannover. The system features an app and a webpage. The app displays the borrowed books, message board, food menu, timetable, widget and lots more and has a service running to notify when a book needs to be returned or renewed. Included is a system to collect usage statistics that is 100% anonymized. For more information write an email.

Official website here.


Resistor color value calculator and trainer

This app is a tool for decoding the color rings on resistors. In additon it can also work as a trainer to help learn the values off by heart.

- calculate the resistor value from colors;
- calculate the resistor color code from value;
- recalculate the values to an E-row value;
- three or four color rings;
- choose what direction to round to (higher, lower or nearest);
- train decoding colors from value;
- train decoding value from colors;
- choose the ratio of what to train of these two modes;


Homescreen notes widget

This is a homescreen widget that displays some notes and/or to-do lists. The ones on the Play Store didn't quite satisfy me. I wanted one that could be interfaced very fast and simply. It stores the notes in a file on the SD-card. When the widget is clicked it starts the editor.
It features 5 screens selected by clicking the top left or right. An indicator shows the current screen. Clicking the bottom opens the editor. The editor is the same size as the widget. There is no need to save the data as it is saved automatically on exiting.
The editor has some extra features. Swiping outwards on the left side beside the text field will delete the coresponding line. This comes handy for deleting to do list items. Swiping below the text will undo an accidently deleted line and swiping on top switches the screens. Note that the red rectangles are just for a better explanation and are not visible in the app.

VGPS - under development

Offline vector GPS guidance

This app is a tool for recording GPS data and displaying it together with the current position. It does not need any data conenction. It is intended for hiking in remote places in order to find back home.
Development of GPS apps is great with the Android Emulator. It is possible to send mock locations through telnet. I made a little tool to send the location from Goolgle earth for better debugging.

- record and save a GPS path;
- load a GPS path and display the current position to the path;
- display the distance to the starting point;
- display the length of the path;
- includes a linear filter;
- service recorder running in the background;
- more to come...