A. 1. Ensure that you are using the OMRON device correctly according to the user manual, as improper usage can lead to inaccurate readings. 2. Take multiple readings at different times and average them manually to compare with the app's readings.

B. 1. Check if the app has a calibration option and follow the instructions to calibrate the device if available. 2. If inaccuracies persist, consider consulting with a healthcare professional for advice.