Again an illegal copy of Periodical

Unfortunately some people ignore the principles of “Open Source” and the GPL. Again I have to deal with an illegal copy of Periodical (also see Again an illegal copy of Periodical and Illegal copy of Periodical). This time it is called “Periods Tracker”, published by “joettaraubapps” (

Many thanks to Marie of for the hint via e-mail!

The procedure corresponds to the known pattern – one takes the sources, removes all references to the original and inserts advertising or offers the app as a paid version. I have already contacted “joettaraubapps” by e-mail and also sent a notice about a copyright infringement to Google.

As a reminder: The GPL is legally binding and derivative copies of my app must comply with certain conditions!

Why I don’t use WhatsApp

Recently you could read the following news at ( (translated):

WhatsApp has a vulnerability (CVE-2019-3568) that allows unauthorized remote access to the device. The attacker can simply smuggle the spyware into a device through a WhatsApp call, even if the called party does not pick it up. Since Monday evening there is a patch.

Also, there were reports last year that WhatsApp will scan messages to show personalized ads, which is probably the case now.

These and several other events of this kind (I also recall the “Cambridge Analytica” scandal on Facebook) have kept me from installing and using WhatsApp on any of my devices and I will not do that in the future.

Those who use WhatsApp should be aware that you are potentially vulnerable. On the one hand WhatsApp’s source code is not open source, so no one knows what backdoors and security vulnerabilities exist, and on the other hand WhatsApp is also an attractive target for attacks due to the huge number of users.

Alternative to WhatsApp

As an alternative I can recommend “Signal”. This is a free messenger whose sources are also disclosed and which is also recommended by security experts. Even Edward Snowden uses and recommends this app. As with WhatsApp, the mobile number for logging in and contacting other people is sufficient, whereby the operator of Signal does not have access to this data and all messages are encrypted and can only be read by the persons involved.

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Positive feedback about Periodical

With the permission of the sender I’m honored to publish a positive feedback about Periodical, thank you very much:

Dear Mr Welzel,

I just wanted to let you know, how much I am enjoying the Periodical app for the last three months. I was using the Flo once before, but it was kinda impractical and never gave me the right information, so after I’ve read how they handle their clients’ information, I was looking for an app that will actually work for me and I found Periodical. I really enjoy how it counts the average lenght of my cycle, how I can add almost any info about my period, the minimalistic design and how it can be easily worked with.

I just wanted to thank you for your work because it trully makes my everyday life much better. Keep up the good work :)

Thank you very very much.

Rudolfová Pavla (Czech Republic)

VueScan – promising product with questionable support

I have an older scanner – a Canon LiDE 210. Canon also provides drivers for Windows 10, but they cause the Windows WIA service to crash quite often. Therefore I decided to look for an alternative and tried VueScan – an application which comes with its own drivers.

Before installing VueScan I needed to uninstall the existing Canon software and the old driver and also tell Windows to remove the driver files as well, so the original driver would not be used any longer.

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Periodical 1.30 released

There is again a new version of Periodical with a number of changes:

  • Events and symptoms in the details are now separate lists.
  • The calendar now indicates if there are events, symptoms or notes for a specific day.
  • Added Greek translation.

With this version there are no less than 13 languages available (soon it will be 14). Thanks to all translators and developers at Crowdin and Github for their contributions!

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Why DAVDroid was renamed to DAVx5

For synchronizing address books and calendars on my Android smartphone I’v been using  DAVDroid for quite a while. It is Open Source and also available on F-Droid. However it is now called DAVx5 – why?

The reasons are explained in this tweet – using “droid” as part of a name violates a trademark of Lucasfilm. Also see this extensive article at Priceonomics. Therefore the creator of DAVDroid decided to change the name to “DAVxxxxx” and replace “xxxxx” by “x5” – even though the official statment says something different ;-).

Fast internet connection

From now on I have a fast internet connection using VDSL100 which nominally provides 100 Mbps downstream and 40 Mbps upstream (before: 50 and 10 Mbps).

Eventhough the achievable speeds are slightly lower, uploading data is still more than three times as fast as before :-).