Updated April 10 with comment from Sony Mobile.

Sony’s long-awaited life-tracking app, felog, hit ay on dnesday— this should be good news for anyone who’s already purchased Sony’s SmartB wearable, which requires felog a Sony host app to work.

But for now the SmartB its mission-critical felog app are only optimized to pair with a single smartphone, the yet-to-be-released Xperia Z2. at’s more, compatibility of any type is limited to Xperia phones running Android 4.4 higher, according to the app’s description on ay.

That could be bad news for people who don’t own these Sony phones, but already purchased the SmartB from Amazon (where it’s no longer for sale) or might still buy the wearable from Newegg. 

I was one of the original Amazon consumers, purchased the SmartB for $99—a far cry cheaper than the $140 Newegg is charging. The product packaging has an Android 4.4 label on it, but doesn’t mention specific hardware requirements. Nor are any compatibility warnings listed on the two retail websites. Yet when I tried to download the essential felog app to both an HTC One (M7) a new Samsung Galaxy S5 (both Android 4.4 devices), my efforts yielded only the heartbreak of defeat.

So now it looks like the SmartB will have only Sony-exclusive hardware support for the time being. This would be a new development for Sony’s wearables effort, as the Smartwatch 2 works with any Android phone running 4.0 or higher.

On Thursday, Sony Mobile shared with me the following explanation concerning SmartB sales compatibility issues: “Unfortunately SmartB was shipped out ahead of schedule by several independent distributors. Globally, we launched the first version of our accompanying felog host apps this week, with more to come on the official distribution of hardware software.”

In case you’re wondering what all the hubbub is about, check out the felog video above. Both the app the SmartB look to offer a fresh new take on activity-tracking, letting users record social media events, entertainment events other lifestyle data to a graphically lush timeline.