Developers said these turnout apps aren’t intended to shame anyone. As Debra Cleaver, the chief executive of the San Francisco-based Vote.org, a nonprofit group that works to increase voter participation, put it: “We call it social pressure or social validation. ‘Vote shaming’ sounds like it was coined by a reporter because it makes you want to click.” (Fair.)

They say their primary purpose is “relational organizing,” or tapping into your social network to tell contacts about a candidate or election (as opposed to the old-fashioned and less effective “operational organizing” that involves dispatching volunteers to cold-call strangers). In other words, coastal liberals can make a difference while fiddling with an app on their sofas (“I know you’re going to vote on Nov. 6, duh, but make sure to remind your friends!” one text template reads), rather than flying to Iowa to knock on strangers’ doors. “I haven’t knocked on a door since 2014,” Ms. Cleaver said.

Buffy Wicks, a community organizer and former Obama campaign aide who was recently elected to the California State Assembly, said it doesn’t have to be “an either/or.” She hosted 239 house parties at which she encouraged supporters to download VoterCircle, but she also knocked on 115,559 doors. More than 100,000 people voted for her.