The San Francisco 49ers entered the 2015 NFL Draft with only two quarterbacks on the roster: Colin Kaepernick and Blaine Gabbert. Even if they remain the only two options when the 2015 season gets started, the 49ers needed to add some bodies for purposes of training camp and preseason reps.
As the undrafted free agency frenzy is underway, South Carolina quarterback Dylan Thompson announced on Twitter that he signed with the 49ers. One of the beat writers mentioned it in regard to the QB position during Trent Baalke's press conference, and Baalke seemed genuinely surprised the signing was done. He might have been BS'ing us, but it was kind of funny, "Oh yea? We got one!"
While discussing the quarterback position, it also came up that Blake Bell had a QB background. He played quarterback his first three seasons at Oklahoma, before switching to tight end in spring 2014. He had some goal line work prior to that due to his size, but 2014 was his first full year away from the quarterback position. When asked about that, Baalke said that the coaches had in fact looked at his QB film last week and brought it to Baalke's attention. Baalke confirmed Bell would be an emergency quarterback for the team moving forward. He also stated that Bell was drafted to be a tight end primarily.
That does not mean Thompson won't have a chance to make the team, but his odds are probably rather long for now. Kap is not going anywhere this year, and Gabbert just signed a two-year deal, so he is probably in good shape, roster-wise. However, with Bell as a potential emergency QB, the specialization makes it easier to save a roster spot from a normal third quarterback.
The 49ers have not made any UDFA signings official, but here are some scouting reports on Thompson. The common theme is good size and strong arm, but horrible footwork: