Seriously, have you seen how many smartphone apps are out there? I'll give you a hint: a metric arseload.
Here, for example, are “9 Intimate Apps for Couples”. Do you really think any of them are going to change the world? Or even be moderately popular? Yet I'll bet their creators are pitching at anyone they can find.
60% or more of smartphone apps don't break even. 80% couldn't sustain a business. The odds aren't in your favour. You're doomed.