Let me start by saying the ZURURU Fitness Tracker has been my workout buddy for the past three months. The purple band adds a pop of color to my gym outfits, and at this price point, it's hard to complain too much.
The step tracking works decently when I'm walking normally, though I did notice it undercounts when I'm pushing a shopping cart (about 30% fewer steps). Sleep monitoring is hit-or-miss - some nights it perfectly captures my tossing and turning, other times it thinks I'm in deep sleep when I'm actually binge-watching shows.
Where this tracker shines is battery life. I consistently get 5-6 days between charges, and the USB plug design means I can charge it anywhere (though removing the band gets annoying). The heart rate monitor seems reasonably accurate during workouts, matching what I see on gym equipment.
Now for the not-so-great: The blood pressure feature might as well be decorative. It gave me the same reading whether I was relaxing or post-workout. Also, the app occasionally forgets my login credentials - frustrating when you want to check your progress.
For $40, you're getting decent activity tracking with some bonus features that may or may not work properly. It's perfect for casual users who want basic metrics without breaking the bank, but serious athletes should probably look elsewhere.