A free app for Android, by Tibor Borsos.

Devices supported:

Zeblaze GTR 3; Zeblaze Btalk; Zeblaze GTR 2; Zeblaze GTS Pro; Zeblaze Lily

Key traits

Collaboration with official Zeblaze apps or independent operation

normal and internet incoming call signal with caller display

missed call signal with caller display

displays the app’s notification texts on the watch

displays the most commonly used emoticons

uppercase conversion emoji and character replacement customization 

Low battery warning

Uploading custom watch faces and editing them

Location-based weather forecasts from OpenWeather and AccuWeather.

Charts of daily/weekly/monthly/yearly steps

Daily/weekly/monthly/yearly pulse charts with measured values, quarter-hourly values, half-hourly values, and hourly values.

Sleep charts daily, weekly, monthly, and annually

Call reject button: call rejecting, call muting, call answering

find my phone

control over music

music volume control phone mute switch Switch flashlight

Hourly event reminders

Mode of no disturb: toggle Bluetooth on/off, call or notification alert on/off.

Export data in CSV format.

Languages spoken include English, Hungarian, Russian, Ukrainian, Portuguese, Spanish, Polish, Czech, Slovak, Turkish, Italian, French, German, Romanian, Greek, Korean, Japanese, and Chinese.