Kaepernick has been available for any team to sign since then, and there has been practically no interest in him. The only known visit Kaepernick has taken was with the Seattle Seahawks in late May. Seattle passed on acquiring him, opting to sign Austin Davis instead. Davis has 13 career touchdowns and 12 interceptions; Kaepernick has 72 career passing touchdowns, 30 interceptions, 13 rushing touchdowns and a Super Bowl appearance.
The lack of interest in Kaepernick led to an ongoing story in which people have accused NFL teams of blackballing him for his protest during the national anthem in 2016. He has filed a grievance against the league and its owners. Here are the quarterback acquisitions that have happened since Kaepernick became a free agent, and some figures associated with those moves, so you can decide for yourself.
Total QBs acquired: 64
Last QB signed: Josh Johnson, Texans (Nov. 7)
Total Super Bowl starts by those QBs: 0.
Total Super Bowl starts by Kaepernick: 1.
Buffalo Bills : * T.J. Yates (April); * Keith Wenning (August); Joe Webb (September); Nathan Peterman (drafted in 2017).
Miami Dolphins : * David Fales (May), Jay Cutler (August), Fales (October)
New England Patriots : Brian Hoyer (November).
New York Jets : Josh McCown (March).
Baltimore Ravens : * Zach Terrell (May); * David Olson (July); * Josh Woodrum (July); * Thad Lewis (August)
Cincinnati Bengals : No free agents signed.
Cleveland Browns : Traded for * Brock Osweiler (March); DeShone Kizer (drafted in 2017).
Pittsburgh Steelers : Landry Jones (re-signed, March); * Bart Houston (May); Joshua Dobbs (drafted in 2017).
Houston Texans : Deshaun Watson (drafted in 2017), *Matt McGloin (November), Josh Johnson (November).
Indianapolis Colts : * Phillip Walker (May), traded for Jacoby Brissett (September).
Jacksonville Jaguars : Ryan Nassib (September).
Tennessee Titans : Matt Cassel (re-signed, March); * Tyler Ferguson (May); Brandon Weeden (October).
Denver Broncos : * Kyle Sloter (May); Brock Osweiler (September); Chad Kelly (drafted in 2017).
Kansas City Chiefs : Patrick Mahomes (drafted in 2017).
Los Angeles Chargers : Kellen Clemens (re-signed, March); * Eli Jenkins (April); traded for Cardale Jones (July).
Oakland Raiders : EJ Manuel (March).
New York Giants : * Josh Johnson (March); Geno Smith (March); Davis Webb (drafted in 2017).
Washington Redskins : No free agents signed.
Philadelphia Eagles : Nick Foles (March); * Matt McGloin (April).
Dallas Cowboys : Kellen Moore (March); Cooper Rush (May); * Luke McCown (July).
Chicago Bears : Mike Glennon (March); Mark Sanchez (March); Mitchell Trubisky (drafted in 2017).
Detroit Lions : *Brad Kaaya (drafted in 2017).
Green Bay Packers : * Taysom Hill (May).
Minnesota Vikings : Case Keenum (April); Kyle Sloter (September).
Atlanta Falcons : Matt Schaub (re-signed, March); * Matt Simms (May); * Alek Torgersen (May).
Carolina Panthers : * Garrett Gilbert ; ** Brad Kaaya .
New Orleans Saints : Chase Daniel (March); * Ryan Nassib (June); ** Taysom Hill (September).
Tampa Bay Buccaneers : Ryan Fitzpatrick (May).
Arizona Cardinals : * Trevor Knight (May); Blaine Gabbert (May).
Los Angeles Rams : * Dan Orlovsky (July); ** Brandon Allen (September).
San Francisco 49ers : * Matt Barkley (March); *Brian Hoyer (March); * Nick Mullens (September); C.J. Beathard (drafted in 2017); traded for Jimmy Garoppolo (October).
Seattle Seahawks : Austin Davis (June).
**Claimed on waivers
***Claimed on waivers, then later waived