Facebook app user agent

I’m seeing a lot of hits that piwik detects as “unknown browser”. Upon further investigation, I discovered that those requests have something in common, they appear to come from a Facebook mobile app.

Example 1:

Mozilla/5.0 (Linux; Android 5.0; Lenovo K50-T5 Build/LRX21M) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/ Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/;]

Device detector (http://devicedetector.net) reports the following:

operating system
    Android 5.0
client (mobile app)
    Facebook 97.0
smartphone device
    Lenovo K50-T5 

Example 2:

Mozilla/5.0 (iPad; CPU OS 10_0_2 like Mac OS X) AppleWebKit/602.1.50 (KHTML, like Gecko) Mobile/14A456 [FBAN/FBIOS;FBAV/;FBBV/40764466;FBRV/0;FBDV/iPad4,4;FBMD/iPad;FBSN/iOS;FBSV/10.0.2;FBSS/2;FBCR/;FBID/tablet;FBLC/en_GB;FBOP/5]

Device detector (http://devicedetector.net) reports the following:

operating system
    iOS 10.0
client (mobile app)
    Facebook 66.0
tablet device
    Apple iPad Mini 2 

What I don’t understand, is since piwik uses devicedetector underneath, shouldn’t piwik properly detect this Facebook app instead of reporting an unknown browser? or at least report the browser engine (Chrome, WebKit, etc)?

Thank you.

Piwik currently only reports Browser clients. Whenever device detector reports another client type Piwik will currently report “unknown”. The issue is tracked at Client detection · Issue #5413 · matomo-org/piwik · GitHub

Oh, that is weird.

Is there anything that I can do to help speed up the development?