Unusable, immediately crashes

[UPD] Upgraded my OS X to 10.11.2; app now starts and works fine, so upgrading rating to 3 stars.
It is not perhaps tremendously more useful than tab in a browser but it does offer certain conveniences and it works.
Would be nice to clarify “compatibility” section though.

[old review text]
Crashes immediately after launch (Exception Type: EXC_BAD_ACCESS (SIGSEGV), Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000).
I am using OS X 10.9.5.
The team behind this app might have had good intentions, but severy lacking in QA.
There are some positive reviews, so I suppose it must work for some luckly ones, but be careful before paying $4.99.

Konst67 about App for Youtube - Pro - Menu Tab