@legrand98,

Just tested the app against my Garmin Smartdrive 61 and the calculation of the arrival time is the same.

You need to check how you have your smartphone setup.....

@fafluhte,

First are you outside?
Are you also using your data connect in the setup of the app.

There is no reason why it should not be the same as your other GPS apps.

Go over all your settings again.