Make it clearer that the application can't be used when OW4 is down

[henrikhorluck]

If OW4 is down it still appears as the app is functional, even though all transactions will fail

This could be solved by pinging (an api-endpoint on) OW4 on a set interval, and add a status screen saying "can't connect to OW4 " or something when that doesn't return the expected result

[FredrikAugust]

There are calls with fetch (I believe), so you could just add a toast to the onError callback.