Individual addition of content suggested by testers

This is an umbrella issue to reference all the individual items suggested for addition in the Marketplace by testers/users, via email, via "report an issue" function or via the contact form of the beta version of the MP or during events.

Suggestion for sources should be added to issue data-ingestion #21.

@dieter , @buddenbohm , @klaus.illmayer , @frank.fischer01 , @matej.durco , @edward.gray , @alex