On paper maybe but only a fraction of the gay population identifies as queer. Visit any gay bar and ask around. You'll quickly see that not everyone identifies to that label.
If Queer was a fully synonymous with gay, the acronym wouldn't be "LGBTQ+" but simply "LGBT+".
There are two different usages here: queer as umbrella term inclusive of LGBT etc, and queer as a specific identity. The usage as identity of its own is intentionally ambiguous/expansive but frequently implies some form of gender fluidity.
The term can also ambiguously imply a particular political stance with regard to the role of gender in society, or more strongly a particular leftist philosophy.
I am gay man, I do not identify as queer, I think that is pretty common. I'm fine mostly with the umbrella term, but also don't identify with enough parts of that politics that I wouldn't use the term myself ever.
The original commenter is right that the apps don't necessarily seem welcoming to the specifically queer identified.
If Queer was a fully synonymous with gay, the acronym wouldn't be "LGBTQ+" but simply "LGBT+".