Also, if you look up the address, it's not an office complex. It's a residential area with single-family homes.
[0]: https://www.northdata.com/M%C3%BCller,+Montgomery,+K%C3%B6ln...
[1]: https://www.bekm.us/black-diamond-suxess-club-gmbh-mario-ore...
And I bet there are no Wozniaks in that garage.
I don't like considering this a signal. We want indie developers to flourish (a business name is little more than paperwork that anyone can get), and it's too easy for the nefarious to buy a "virtual office" in a legit-looking office building that is little more than a PO Box.
They have a contact form and it's quite normal here in Germany that you have to contact the business first before you can download the business software.
All in all most normal small IT companies I know in my area have a similar looking website.
Which makes it more unserious is that one of the Managing Directors has done shady business in the past.
[0] www.unicomedv.de