Wireless pull stations & notification system on the phones

Hello,

I have just a little knowledge on the fire alarm system. So I am seeking help here.
Our non profit organization is at the remote Sierra mountain in California.
There are around 20~30 small / medium size buildings scattered around 1500 ft radius. Those are on the hill side and also there are a bunch of tall / short trees.
So wire connection to each building is challenging and we have a limited funding, and looking for a wireless solution.

We found Honeywell Swift Pull Stations and some compatible FACPs.
We want to get the notifications from which station is triggered on our mobile device or sort of.
What will be the best and cost reasonable solution for our project.

Thank you.