When Uber starts selling its shares to the public for the first time on Thursday, the ride-hailing app could be worth as much as $91 billion. Those who already have a stake in the company could become very, very rich.

But the drivers who rely on the app for income won’t.

Drivers in New York and other cities have complaints about the company, and they’re planning a strike tomorrow morning to raise awareness about their grievances.

How will drivers strike?

Drivers who work for Uber and similar ride-hailing apps, like Lyft, Juno and Via, plan to sign off the apps from 7 to 9 tomorrow morning. Customers will be able to log on to the apps, but they may not find many drivers nearby.

After 9, drivers will resume picking up passengers.

What are the drivers protesting?

In short, they want better pay and working conditions.

The drivers’ demands were outlined in a statement from the New York Taxi Workers Alliance. One request is a limit on how much money drivers have to share with the apps per ride. The group also opposes what it says is Uber’s practice of arbitrarily removing drivers from the app, effectively terminating them.