See here for general instructions on how to connect tracking apps/devices to Count.It via Google Fit and Apple Health. Below are specific instructions for using your Runstastic app with Count.It.
Connecting Runtastic to Count.It via Apple Health
1.) Follow these steps to activate Runtastic synchronization with Apple Health:
Tap the “Profile” tab
Tap the gear icon in the top right corner
Select “Partner Accounts”
Enable Apple Health
To select the data that you wish to be synchronized, open your Apple Health app and open “Sources”. (For more details, check the Runtastic support site.)
2.) Download and install the Count.It iOS App from from the iTunes store. This will allow Count.It to get your Runtastic activity data via the Apple Health app.
Connecting Runtastic to Count.It via Google Fit
1.) Connect Runtastic with Google Fit.
If you don't already have it on your phone, download Google Fit from the Google Play store.
Follow these directions from the Runtastic blog: "Make sure you sign into Runtastic with your Google+ account, or sign in and link your Google+ account to your Runtastic account on Runtastic.com. Then, in the Runtastic app, go to ‘Settings’ then ‘Partner Accounts’ and click ‘Connect’ next to Google Fit."
2.) Turn on Google Fit sync'ing on your Count.It Settings --> Trackers page.
Log in to Count.It, and go to Settings --> Trackers
Click the "Connect" button next to Google Fit
Log in with your Google Fit username and password