To be honest, I think there are way too many apps out there just like yours that are way way better. So instead of putting effort into marketing your app, I would put effort into making an app that fills a need that no one else fills instead.

Let the product do the marketing for you. Of course you need to do a little marketing yourself, but the more unique the product, the more your marketing efforts will scale it. In turn, I think with your product you can do a looot of marketing and nothing will come out of it, because the product isn't unique enough.