GSender is free but, why?

There are many great free open source software packages. Many people aren’t aware of this. Just to name a few…

Libreoffice
Inkscape
Thunderbird
many browsers, Firefox/Chrome/etc/etc/etc
GIMP
Irfanview
Stellarium
VLC
Audacity
OBS Studio

And on and on…

I’m a big fan of the portable apps platform, go to portableapps.com and check it out. A great app that organizes a huge selection of free applications that you can run from anywhere, even a USB key without any installation at all. And a really nice menu system to arrange and find things. All for free.