Enabling syncing of data between Apple Health and Qardio App is easy.
In the Qardio App simply tap on the menu icon in the left upper corner and select Settings.
In the General section in the Settings menu there is an option to enable syncing with Apple Health. Enabling the switch will allow you to select which metrics you want to share between Apps.
The Apple Health integration is only available on iOS.
Readings that are synced from Apple Health to Qardio, will be displayed in your history list with a small Apple Health icon next to them.
To enable integration with Google Fit, select the "Q" menu on the top left of the screen, and tap on "Settings." Scroll down to QardioBase and enable the switch for "Connect to Google Fit."
A popup will appear asking you to Connect to Google Fit, choose "Connect to Google Fit."
The next screen will ask you to choose your account. Select your account and tap Add account.
The last screen will request you to allow data storage in Google Fit, choose Allow. Now your Qardio App will share your weight data with Google Fit.