I think it could definaltey be an app that steemains could have fun with. You could add a competition/refferal element so after I complete I add a user name or tag them to try it, this will allow the community to get the word out and grow it.

Pop into the various discords that do competitions like @steembasicincome and @contestkings i'm sure they would be able to help you promote it.

Also look at combining @steem.ninja so non steemians who find your site can easily sign up with a steem account and try it out