A:AnswerYou'll be able to track your heart rate w/o cost but to track oxygen levels you'd need to purchase the Fitbit + plan (I think that's what its called). The Fitbit Versa3 is your best option for integrating apps from your phone to your watch & monitoring your health.
A:AnswerYou can sync your calendar on your phone to your Versa3. The watch will show you appointments for the current day and the next day only. If you set reminders on your phone calendar you will get them on your watch too (must turn on notifications).
A:AnswerAlthogh we havnt used the music feature, the way I understand it is it can connect to your phone via Bluetooth if it is close enough fir music or texts
A:AnswerShould work with just about any Andriod phone. Best way to find out is to buy the fitbit and try it out. If it doesn't work take the fitbit back within the the 14 day return window.