Considering the speed of this signing is obviously a back-up plan for Olindo Mare. The advantage of UDFAs is that they can join in practice immediately, while FAs have to wait until they are officially signed on July 29th.
His bio is available here. He ranks in the top-5 all-time in several categories for Auburn, including fourth in field goals made percentage (74.1%). Scouts point to him being a clutch kicker and accurate overall.
DK Edit: Per an AJC scouting report, Bynum is "considered one of the more reliable kickers in the nation, (he) finished his collegiate career by making 60 of 80 field goals and missing just three of 186 extra points." He went undrafted because his long-range ability may be sub-par.
"However, he's likely to go undrafted due to his struggles on kickoffs and from long range. He may have to prove in training camp that can improve in those areas. Only five of his kickoffs resulted in touchbacks last season. Byrum's issues from long range were also evident on field goals, making 15 of 26 attempts from 40 yards or more. He was impressive inside of 40 yards, connecting on 45 of 54 chances over four seasons."
As for the kickoffs, perhaps the new NFL rules will help there. The long range (40+ yards) field goals will be his biggest weakness, and could pose a problem in his ability to make the roster.