I ordered the Etekcity EFS24 at Walmart (where at $19.99, it's $5 less ATM than Amazon).
It's an inch bigger in both directions than the Etekcity EFS-551, also calibrates and starts much faster according to one customer comparison. Both have Bluetooth app support. Both likely extremely accurate, although I'm more certain about the EFS24.
You need bare feet to get anything going other than just weight, but that's fine.