I get mailers from them every election. We used their app in 2020. Their app "went out of business".
While it certainly is not illegal to do this, it is pretty much a waste of time and effort.
Here is their defunct voter registration app:
https://mapthe.vote/lander
As to why a tech company would leave up a defunct URL is beyond me.
https://directory.civictech.guide/listing/map-the-vote
https://web.archive.org/web/20220116052839/https://mapthe.vote/
Help your neighbors register to vote.
MapTheVote aggregates publicly available data and provides analysis on locations that are likely to have unregistered, eligible voters living at them. The map is a guide to help coordinate and improve voter registration around the country. It has been built primarily by volunteers from many organizations, and is funded by Register2Vote and its founders. MapTheVote doesn't expose any personal data it's just a way for those who wish to register voters in their communities to more easily connect with potential voters.
Status: Inactive
Last Modified: 8/1/2023
Added on: 6/22/2021