How to extend or create a new a cer certificate for package signing or re-signing UWP for sideloading?

How to extend or create a new a cer certificate for package signing or re-signing UWP  for sideloading?

How-I-fixed-it?

1.  Lookup the CN (Publisher Name) from the old certificate (the new one needs to have the same CN) 
2. Command window in current dirctory of the appx
3. 1. Create a new certificate to self-sign you UWP app using the MakeCert in the Windows Kits SDK, e.g. "C:\Program Files (x86)\Windows Kits\10\bin\10.0.18362.0\x64\MakeCert" /n CN=YOUR_PUBLISHER_NAME  /r /h 0 /eku "1.3.6.1.5.5.7.3.3,1.3.6.1.4.1.311.10.3.13" /e "12/31/2100" /sv Test.pvk Test.cer
4. Convert the certificate to pfx format (using the password you entered when promted by the signtool), e.g. "C:\Program Files (x86)\Windows Kits\10\bin\10.0.18362.0\x64\Pvk2Pfx" /pvk  Test.pvk /pi "pwd" /spc Test.cer /pfx Test.pfx /po "pwd"
5. Sign the appx, e.g. "C:\Program Files (x86)\Windows Kits\10\bin\10.0.18362.0\x64\SignTool.exe" sign /fd sha256 /f "Test.pfx" /p pwd "FULL_PATH_TO_MY.appx"

Found the solution here:

https://blogs.msdn.microsoft.com/wsdevsol/2014/02/12/create-a-windows-store-appx-package-and-sign-it/

Windows 10 search app icons broken, only white cross on black background

When I do an Cortana Search on my Windows 10, all app icons in the search results are broken:



How-I-fixed-it:

Press the Start key and type the word CMD, right click on the command prompt and select Run as administrator, enter the following commands one by one followed by the Enter key: 

•- DISM.exe /Online /Cleanup-image /Scanhealth
•- DISM.exe /Online /Cleanup-image /Restorehealth
•- DISM.exe /online /cleanup-image /startcomponentcleanup
•- sfc /scannow 

Reboot.

The answer is based on:
https://answers.microsoft.com/en-us/windows/forum/all/windows-10-search-app-icons-broken-only-white/14f57c34-9cac-4cb8-a133-0680da67aae4?tm=1560262812629

How to make an andorid phone kid safe / Android-Handy kindersicher machen

I was looking for an app to make my kids' android phone more kid safe and restrict internet and app access.

How-i-fixed it:
I found the great free app "Kids place" on google marketplace.
I allows to define a PIN number for administratration and lets you select the apps the kids see on their home screen. It also lets you configure the internet access. I re-routes the home button to the Kids Place home screen and also can be configured to Auto-Start.

I found the right hint to this great app here:
http://onsoftware.softonic.de/so-machen-sie-ihr-android-handy-kindersicher