Lewis played 24 games in two seasons with the Eagles, who selected him in the fifth round in 2011. He rushed for 171 yards on 36 carries and scored two touchdowns. The 5-foot-8, 195-pound Lewis also returned kickoffs for Philadelphia as a rookie and will likely be a candidate to take over those duties for Cleveland. The Browns didn't re-sign Pro Bowl specialist Josh Cribbs this off-season.
Lewis averaged 21.6 yards on 31 kickoff returns in 2011.
Acho spent his entire rookie season on injured reserve after injuring his knee. The Browns selected the former Texas linebacker in the sixth round last year.