Just opened my Windows phone, went to Store to do a search, and found this free app - Diabetes Manager by Collective Wisdom Now. https://www.microsoft.com/en-ph/store/p/diabetes-manager/9nblggh0ckrr
You can choose mmol/L, set goals, enter readings, check progress, export data via an email.
I've just installed it, and will enjoy seeing how I get on.
Hope it works for you !