The PLAN Foundation does so, in part, through litigation, direct services, and the publication of cost-free legal resources.  The press release for PLAN's current jail voting litigation can be found here.  The complaint is here.  The PLAN Foundation recently produced jail-based voting toolkits with the Legal Defense Fund.  Those toolkits can be accessed here and here.

The Lawyers For Equal Access To Advocacy & Dignity Foundation Incorporated, which also operates as the Prisoners Legal Advocacy Network Foundation ("PLAN Foundation"), also administers the non-partisan Election Protection Jail & Post-Release Voting Working Group in partnership with the Lawyers’ Committee for Civil Rights Under Law, NAACP Legal Defense Fund, National Association of Criminal Defense Lawyers, The Sentencing Project, Common Cause, State Voices, Campaign Legal Center’s Restore Your Vote Program, The Advancement Project, The League of Women Voters of Florida and Virginia, Southern Poverty Law Center Action Fund, and New Jersey Institute of Social Justice. This Working Group is a program of Election Protection, the largest nonpartisan coalition that protects, advances, and defends the right to vote in the U.S. 

The Working Group informs presently and formerly incarcerated voters of their voting rights under the law, assists system-impacted voters in overcoming barriers they encounter in their exercise of these rights, and advocates for the expansion of these voting rights. It also develops Know Your Rights guides for system-impacted voters and provides them free of charge to eligible incarcerated and formerly incarcerated voters.