Ann: Half Yearly Report and Accounts, page-35

I guess the simple way to look at it is this;
App downloads are directly proportional to watch sales to customers rather than watch sales to retailers (who will likely have some of their watches sit on the shelf for a while - no app downloads for those watches even though they have been reported as sold by MGM to the retailer).
“Over 6,200 monthly App subscribers as at Dec 31, with a further 3,100 added in January 2019.”
This tells us that combined sales to customers (not retailers) grew by 50% in January alone compared to the total sales to the end of December, since launch. We can therefore see that sales have continued with a lot of strength since the January update.
From all the info to hand there were probably at least 10,000 sold to customers between launch and end of December (based on how many were sold to retailers and how low JB stock levels were by Christmas plus adding sales made prior to JB joining us). That would put customer purchases at around 5,000 for January. If you keep it simple and assume no further growth in Australia/NZ, that works out to 60,000 watches per year before allowing for Europe. Last years figures and the January results show quarter on quarter growth and no sign of that changing.