Murphy, who is currently developing a similar application for Save the Children, said his clients seek out mobile tools as a way to stay in touch with individuals who donate much in the same way they might have used direct-mail campaigns in past decades.
"A key issue for nonprofits is how do you keep people in the loop," he said. "The mobile benefit is that it is keeping supporters close to the organization."
Those individuals can then be called upon to deliver tens of thousands of phone calls or letters to Congress at a moment's notice and with little effort on their part.
Davidoff said ONE expects to have more than 100,000 users for its app by next year. The global group plans to make it available for non-iPhone users and to customize it for lobbying foreign governments.
Digital lobbying may streamline the process, but some question its efficacy.
Christopher Kush, CEO of Soapbox Consulting, trains activists on how to lobby Congress. In 2000, he published a book called "Cybercitizen" that predicted the Internet would lead to a "re-launch of American democracy."
A decade later, he is not so sure.
"Really participating in the battle over issues takes a long-term commitment. ... Somebody whose expectations are instant, could you count on that person to stick with the issue? I don't know," he said.
Kush, who has organized in-person advocacy events for ONE, said substantive lobbying by a few hundred dedicated activists is more effective than electronic form letters sent by thousands. Mobile tools may help groups engage activists, but their growing popularity risks adding to rather than cutting through the noise.
"Anyone who would suggest that in a busy, tech-savvy world, that Americans now simply need to click on their phones and the United States Congress will be processing that, I think that's an overstatement of how this stuff could be useful," he said.
Part of the problem is that, while other industries have adopted new technologies, government and its influencers are still conducting business in old-fashioned ways, state lobbyist Shawn Miller said.
The Oregon resident developed a mobile app, VoteCount, to do away with the pen-and-paper counting methods lobbyists use to track votes.
"We have to be behind the curve if we're still using paper," he said.
Still, he agreed with Kush that technology cannot replace the value of relationships with lobbyists and advocates trying to influence policy.
"I don't see [apps] changing the more personal aspect," Miller said. "That's pretty central to what we do."
Rep. Elijah Cummings, D-Md., right, hugs Harold Schaitberger, General President of the International Association of Fire Fighters, after the Congressman spoke at the IAFF's Legislative Conference General Session at the Hyatt Regency on Capitol Hill, March 9, 2015. The day featured addresses by members of Congress and Vice President Joe Biden.