Real-world conditions

Language, time, theme and battery

Switch the device to a dark theme, another language or time zone, and a nearly empty battery, without digging through Android settings.

Why: half of UI bugs show up only for some users: dark theme, long German words, another time zone, a phone at 5%. Each of them is one click away in the cards next to the phone.

What happens

Display: turn on Dark theme and look for text that disappears and hard-coded colours. Brightness and font size are here too.
Language: pick a system language. Android switches without a reboot; check translations, long words and date formats.
Date and time: change the time zone, and on a real phone move the clock itself to test expiring offers and subscriptions.
Battery: set a low charge, charging or battery saver.
Every changed card gets an amber dot, so you see what differs from a normal phone.

Good to know

These settings apply to the whole device, not only to your app, and stay until the session ends or you change them back.
A virtual device runs on the server’s clock: its time zone can change, the time itself can’t. Real phones can move the clock or set an exact moment; turning Real time off stops Android from syncing it back.
The Language card also adds keyboard layouts, so the on-screen keyboard can type in that language. Some real phones can’t change the system language without root; there the card sets the app’s own language instead.
Battery saver unplugs the charger, because Android turns the saver off while charging. On some real phones the charge level can’t be faked, only the saver.

If it doesn’t work

The app ignores the dark theme: it doesn’t follow the system theme. That is worth a bug report on its own.
The language didn’t change in the app: the app may have its own language setting, or read the language only at start. Restart the app.
There is no way to shift the clock: you are on a virtual device; only the time zone can change there.

More details: Device controls.