Early version of an app (4)

I believe the answer is:
beta
(Other definitions for beta that I've seen before include "Old character" , "Second highest grade of mark" , "second class grade?" , "final test" , "Second Greek letter, B" .)
I believe the answer is:
beta
(Other definitions for beta that I've seen before include "Old character" , "Second highest grade of mark" , "second class grade?" , "final test" , "Second Greek letter, B" .)