You cannot manually log a test in the Nima app. Results appear in the app automatically once your Nima has been paired with your mobile device, then you will be allowed to add information associated with the test.
If several people in your household are using Nima, we suggest a single account to log all your tests. Multiple people can login to the same account through their own device. Just remember - your Nima needs to be paired to the device of the person who is trying to log the test.