Pretty much everything has been said above. but I'd like to add this:
If you also want to track your holdings across different exchanges, or other coins than BTC then you could look into some portfolio trackers like Delta.app, CoinTracking, coinStats, etc.
If you're going to link your exchange account, make sure you're only linking a read-only API key. You wouldn't want to give the app anything else that would allow them to place orders, or withdraw your funds for example.
This is obviously not something I would recommend doing if you value your privacy.