I recommend that it be free and open-source. To quote Gwern:
A closed-source program or library can, by definition, only be worked on by its owners and those the owners permit; while a FLOSS program can be worked on by its owners and anyone in the world with bare access to the source. A closed program developed by a firm dies when the firm dies, and businesses lose interest or die all the time...
Open-source software is also more trustworthy for those who care about internet privacy, an area in which mainstream dating apps are notoriously bad.
I recommend that it be free and open-source. To quote Gwern:
Open-source software is also more trustworthy for those who care about internet privacy, an area in which mainstream dating apps are notoriously bad.