The Vote4DC app, which lets D.C. residents register to vote online, is no longer available because of technical problems.

The app was part of a larger push by city leaders urging residents to request their absentee mail-in ballots early. But, as requests began pouring in, the information infrastructure to process them was “overwhelmed,” the D.C. Board of Elections said in a recap of the June primary.

Those problems affected the Vote4DC app, which, the board found out, was not compatible with all mobile phones.

In addition, voters who used the app to register to vote and request mail-in ballots did not receive confirmation or tracking information about their requests, adding to the confusion.

The D.C. Board of Elections said the private vendor responsible for the app did not respond to “numerous” requests to fix the glitches.

It said, though, that 92,000 ballots were processed and mailed to District voters.

Still, the quiet removal of the app — which allowed new voters to register and existing voters to update their profiles — frustrated some residents.

The group DC for Democracy tweeted that though it understands the move, “the lack of communication with the public is deplorable.”

The removal of the app also puts the city behind 40 states that have online voter registration, according to the National Conference of State Legislatures.

Residents can still register by visiting dcboe.org, but they must print out a registration application from the website, and either mail it in or scan and send it via email.