About me

I'm +Felix, a IT lead platform engineer, Android enthusiast/developer and kite surfer living in Hamburg Germany. I'm developing mobile apps since 2005 starting with J2ME, switching to Android in 2009.

About my projects

Most of my apps are releasd as open source under GPLv3. Feel free to fork the projects on and share your code with me. Helping with translation to your favourite language is appreciated too.


My own projects

Call Meter 3G

Call Meter lets you keep an eye on your mobile plans. It tracks calls, messages and mobile data traffic. A huge amount of billing modes is supported and configureable. It's flexible but complex.

There is a list of rules available ready to import directly into your Call Meter 3G app. Just pick the one fitting best and change the settings for a exact match of your providers billing mode.

Call Meter 3G is the complete reimplementation of Call Meter NG. It has a huge amount of new features like widgets, alerts and tons of new supported ways to set your plan.

Call Meter NG

Call Meter lets you keep an eye on your mobile plans. It tracks calls, messages and mobile data traffic. A few different billing modes are supported.

Call Meter NG is the first app in the Call Meter series done by me. Since the beginning of 2011 Call Meter NG is declared as deprecated. The complete reimplementation Call Meter 3G is more flexible, accurate and complex than Call Meter NG.


WebSMS sends free and cheap TXT via different webservices. WebSMS lets you send free and very cheap TXT/SMS via different webservices.

You will need at least one WebSMS Connector (plugin/extension) from play store to connect this app to the webservice of your choice. Pricing depends on the webservice provider connected with the connector. The "SMS" Connector shipped with the app itself sends messages via standard GSM method and is billed by your operator. It is installed for backup reasons and deactivated by default.


SMSdroid was made to read TXT messages and reply directly with WebSMS without the need of switching apps. SMSdroid is kept as simple and clean as possible.

Ingress Portal Timer

Portal Timer is a very simple Android app sitting in your notification tray and times your ingress portal hack cool down periods.


WiFiBarcode lets you share your WiFi configuration via barcodes/QR-codes. What's make it special, is that root users can share the WiFi password within the barcode.

pixel sheep

Pixel sheep is my first Live Wall Paper (LWP) for Android. It shows a little cute sheep walking anywhere you click on your desktop. It shows sunrise, sundown and current weather conditions.


TravelLog is a one-click-app to log your business trips for later accounting (time recording). Location based logging turns it into a zero-click-app.


OTPdroid is an One Time Password (rfc2289) implementation for the Android. It is used for logging into a (OTP enabled) system from an untrusted terminal by generating a password that is only valid for one login.


Tired of telling your girlfriend to switch on the ringtone? Don't want to miss calls from some people? RingRing is what you need!

Clipboard Beam

Clipboard Beam reads your clipboard and beams the content to your buddy with Android Beamâ„¢...

Missing Keys

Miss some keys on your T-Mobile G2 / HTC Desire Z' keyboard? MissingKeys is what you need! Bind it on your hardware hotkey and put any text you want to clipboard with only one click.



I made some changes to the mighty CyanogenMod to attach more than one NFC tag to a profile and to let you set airplane mode and ringer mode in profiles.

Further references


I'm currently about to create an app for Terminbuddy. It's an end-user app browsing through a list of dressers and book appointments on the way.


I made an app for Groupon's customers. It's focus is scanning the coupons's barcode and check/redeem them with use of a web API.