I have used various generic apps, but now just stick to my Contour Next app that my phone can share data via bluetooth to.
When I did use a generic app it was called Diabetic Journal Pro, but the original dev sold it to some shonkies and it was made absolutely useless by crashing all the time.
I use the Contour Diabetes App, it connects to my Contour Next One meter via bluetooth and sends all readings automatically straight to the app in my phone. The app can also generate reports and readings for sending to your dr's and specialists.
If you go to Ascensia Diabetes Care UK website, you can apply and get a Contour Next One meter for free.