Count.It does not directly support connections to the Mi Fit app, or Mi Bands. That said, users with Mi Fit/Mi Band can sync their data to Google Fit, which Count.It does support. Following are the steps to get connected, (courtesy in part of The Verge.)
Open the Mi Fit app and tap the profile button on the lower right corner.
Scroll down and tap Add accounts. Mi Fit will offer to automatically pair with WeChat and Google Fit. Select the Google Fit option and confirm the sync. You will now begin to see your activities show up on Google Fit.
Now you should turn off activity tracking on Google Fit. If you don't do that, Google Fit may overwrite the data that it is receiving from your Mi Fit. With Google Fit still open, tap the “Profile” button in the bottom toolbar, then tap the "Gear" or settings icon at the top right of the screen.
Scroll down and confirm that “Track Your Activities” is disabled.
Google Fit will now receive the data from Mi Fit or other connected tracker, but not overwrite it with its own tracked activities.