The Karma Hotspot appears to be one of those apps that overshares, but it isn't.
The Hotspot acts as a go-between to connect a Wi-Fi phone, tablet or computer to the Web using the mobile phone network.
It gives away data — 100 megabytes' worth — when you sign up, and each time you allow someone to share your hot spot. That 100 megabytes is equivalent to downloading about 300 emails or 15 good-quality 3 1/2-minute songs.
Karma's registration is through Facebook. Here is where the confusion comes in. When you sign up with any app through Facebook, it asks if you want to allow the app to share information. If you say yes, you will see a message telling you that Karma can share posts on your timeline. But although the mechanism is there to share, the app doesn't send any automatic notifications, the company said.
In a test, Karma sent no unwanted alerts.
As for how the app works after the sign-up, the data speed isn't blazing. Although the device promises 4G speeds, in a test the average was 1.8 megabits a second, less than half the speed on an AT&T LTE network, and too slow to run YouTube videos without freezes.
The roughly 3-inch-square Karma hot spot costs $80. If you just want data without signing up friends, it's $14 a gigabyte.