After using the APPBYER Fitness Tracker for a few weeks, I can confidently say it's a great budget-friendly option for those looking to monitor their health and fitness. The 1.10-inch AMOLED screen is crisp and bright, making it easy to read even in sunlight. Navigating through menus is smooth, and the touch response is surprisingly good for the price point.

The heart rate, blood oxygen, and blood pressure monitoring work well enough for casual tracking. While I wouldn't rely on it for medical-grade accuracy, it gives me a good general idea of my vitals throughout the day. The sleep tracking feature is decent but could be improved - like many reviewers mentioned, it sometimes mistakes my pre-bedtime stillness as sleep time.

Battery life is where this tracker really shines. With moderate use (continuous heart rate monitoring + occasional workout tracking), I easily get 10-12 days between charges. The magnetic charging is convenient and secure.

The waterproofing works as advertised - I've worn it swimming without issues. However, like one reviewer pointed out, prolonged exposure to chlorinated water might damage the seals over time.

My biggest gripe is with the companion app 'Keep Health'. While functional, the constant push for premium subscriptions is annoying. You can use basic features without paying, but the upsell attempts are persistent.

For under $50, you're getting a lot of value here - multiple sport modes, decent health tracking metrics, and reliable basic smartwatch functions. It's not perfect (the sleep tracking could be smarter and the app experience better), but as an entry-level fitness tracker, it gets most things right.