Call-to-worship songs are most often sung by the congregation to each other. Take "Sing To The King":
Come, let us sing a song, a song declaring we belong to Jesus; He is all we need.
This is different than "Here For You":
Let our praise be Your welcome...We are here for You.
Both songs are "we" and "us" songs, but the intended audience for "Here For You" isn't in the seats. It is Jesus, and this takes the song to another place.
The Spirit behind the song
Matt Maher, one of the writers, refers to it in two ways: a welcome song and a motivation song. The welcome part is pretty obvious; the motivation part a bit more intuitive.
The appeal of this song is that as believers, our hearts long for Jesus. We want to experience his "breath from Heaven" and we want his Word to "move in power". And when that doesn't happen, our soul cries out – even when we don't recognize or acknowledge it.
Have you ever reached the end of your day only to realize you didn't acknowledge God? You didn't once ask him for help or for his Spirit to guide you?
What about this: Do you ever study the Bible, even journal, without first praying and asking God to guide your mind and your heart? I formerly did this all the time! I still do it occasionally. If I'm not careful I'll open the Bible with a cavalier attitude and write out my thoughts without ever welcoming Jesus to the conversation of my heart and His (represented through the Word).
But when I do, when I do welcome him to join me – whether it be approaching the Bible or walking into a conversation – in that moment I feel joy in my spirit. Something comes alive that is truly transcendent.
In the same way our hearts long and love to sing "we welcome You with praise".
Matt doesn't refer to "motivation" as if to say the song is motivational (although that is a secondary byproduct). Matt is referring to the audience checking their internal motivation. As the psalmist preaches to his soul, "Why so downcast oh my soul? Put your hope in God!", so too are we taking inventory of our soul and correcting our motivations.
As we correct our motivations, may our hearts not be set on us. May our songs not fill time or warm up people to hear the sermon. No, let our "songs be a sign" that "we are here for You". We are not relying on a man behind a guitar or a man behind a pulpit. It is only "Your breath", Lord, that will "fill our hearts with Your life".
“I [imagined] an arena full people declaring 'God, there are a lot of different reasons we can be here, a lot of different motivations, but ultimately we are here.' And so we looked at this idea of a song welcoming God." – Matt Maher on the genesis of "Here For You"