I agree, this seems like a product that would be open source. Seeing stuff in the planned section on the development page made me want to contribute as some of it is *right* up my alley. There are many examples of apps that are paid to download, but have source code available to allow community contributions. Some examples are Tampermonkey ($1.99), Cyberduck ($23.99), Cryptomator ($11.99), MarkText ($2.99) or FSNotes ($4.99)