Every month, I highlight the state of the Windows Phone hardware ecosystem, using data from AdDuplex to see which handsets are the most widely-used. Not much has changed this month, as you might expect, but I’m interested to see news of a coming flagship (!) plus a much-needed peek at the smaller Windows Phone handset makers in the report.

As you may remember, AdDuplex bills itself as the largest cross-promotion network for Windows Phone and Windows 8 apps, empowering developers and publishers to promote their apps for free by helping each other. And each month it provides a tantalizing glimpse at which Windows Phone (and Windows) devices people are actually using.

Note: Also please remember that this data measures handset usage share within the market for Windows Phones. It does not compare Windows Phone usage (or sales) to Android or iPhone.

Here’s what’s happening this month with Windows Phone device usage.

Very little change at the top of the charts. The top ten most used handsets remain unchanged from March, and the devices most in contention—the Lumia 635, which is still on the way up, and the Lumia 520, which is still on the way down—both changed very little.

Perhaps Lumia has crested. Microsoft/Nokia branded phones finally declined in usage, albeit a piddly .11 percent to 96.54 percent of all Windows Phone handsets in use. HTC (1.85 percent), Samsung (0.75) and Huawei (.44) round out the top four.

Windows Phone 8.1 continues to gain and establishes 72.5 percent usage share this month, with Windows Phone 8.0 falling to 18.3 percent. Windows 10? .7 percent, which is actually a huge leap from the .1 percent we saw last month. (Windows Phone 7.x is 8.5 percent.)

USA: All low-end at the top. The top five phones in the US—Lumia 635, 521, 520, 630 and 530—are all low-end devices.

USA: AT&T rules. AT&T commands the US market for Windows Phones with 33.2 percent usage share, compared to 20.1 for Cricket, 17.8 for T-Mobile, and 12.5 for Verizon.

Europe: All low-end at the top. As with the US, the top five phones in the EU5 (France, Germany, Italy, Spain and Great Britain)—Lumia 520, 630, 635, 625, and 530—are all low-end devices. It’s nice to see the Lumia 930 (with 4.4 percent usage) in there though.

Yes, Virginia, there is a flagship coming. AdDuplex has finally caught sight of a new Lumia flagship in the wild. The RM-1085 is a 5.7-inch 1080p device running Windows 10 Mobile. Be still, my heart.

Of much more interest, to me anyway, is AdDuplex’s look at new Windows Phone hardware makers. As you can see from this chart, which breaks down the “other category” in worldwide usage (just .42 percent of all Windows Phone handsets in use), there are a wide number of other phone makers, each making a tiny dent in the market. Not surprisingly, again to me at least, is that BLU is the biggest of this group. I’m surprised they haven’t already surpassed Huawei and Samsung, frankly.