Probably the same as all BLE apps. Because it’s not based on the app, but the device (particularly the antenna) and environment. Some thoughts to help you frame this:

More obstructions / “stuff” between you and another device, the more interference and multipathing.

If you’re out in a field or on a road and have line of sight, you can go a decent way.

If you’re moving, it will be variable.

Every antenna emits a radiation pattern. For a simple dipole, imagine a donut. The other device is also a donut. When the two donuts intersect, they can talk to each other. Transmit power affects how “loud” they can talk while the donut pattern affects how much they can “hear”.

Transmit power is how you can maybe overcome other devices and environmental interferences (like a lamp post, WiFi, power lines).

As you can imagine, your phone doesn’t have pointy antennas coming out of it. If you were to view the BLE antenna, it’d be smaller than a dime in size (with a particular and clever radiation pattern). Your phones battery is a clear indicator that you aren’t transmitting very loudly, but that’s the point of BLE.