NEW YORK - On-demand apps make life easier: A few taps on my phone and I can get a cab in minutes or groceries delivered to my door.
The hard part? Figuring how much -- or if -- I should tip the people who drive me around or pick out my cheese at the supermarket.
Part of the confusion arises from the companies themselves. Some don't allow tipping through their apps, even though they say tipping is allowed. And the policies posted on their websites can be unclear.
Just like other service professionals, we should tip these types of workers, says Sharon Schweitzer, etiquette consultant and founder of Protocol & Etiquette Worldwide. Many of them have to reach into their own pockets to pay for gas, bike repairs or other costs, and a tip can help them make ends meet, Schweitzer says.
"The apps are designed for us to evolve to a cashless society," she says, "however that doesn't mean we become heartless in the process."
Indeed, cash is best if you have it. Some companies, like FreshDirect, will deduct processing fees that credit card companies charge before paying the driver, so they won't get the full amount of your tip.
Click ahead for some tipping suggestions from etiquette experts.
Uber doesn't allow users to tip through its app because it wants to keep the ride cashless. You can tip if you want to reward good service, however, and drivers can accept -- Uber clarified its policy to say so after recently settling two lawsuits filed by drivers -- just remember to bring cash. Rival service Lyft lets customers tip through its app within 24 hours of the ride.
Forgot the cash? At least give their driver a good review on the app, Schweitzer says.
Tip: 20 percent of the cost of ride.
Workers for Instacart, Postmates and other grocery-delivery services often need to wait on long lines and carry heavy items. When calculating a tip, base it only on the cost of the food, says Callista Gould, and etiquette instructor and founder of the Culture and Manners Institute. You might want to tip at a higher percentage if they're carrying your goods up several flights of stairs or if the weather is bad.
Tip: 20 to 25 percent of grocery costs.
Seamless, Grubhub, Eat24 and most other restaurant delivery companies allow tipping through their apps and websites, but give them cash if you have it. Bigger orders, such as for an office party, should get a higher tip percentage.
Tip: 20 to 25 percent of food order.
Just because you skip the hotel and rent a place through Airbnb or HomeAway, you shouldn't skip tipping the housekeeper. Often, owners of the property hire people for clean up, Schweitzer says. To ensure the money gets to the right person, Schweitzer says she leaves tips in an envelope addressed to housekeeping under a pillow or near the dirty towels. (No, you don't have to tip the host.)
Tip: $3 to $5
Apps that send someone to pick up dirty laundry and return it clean have been popping up in big cities around the United States. One of those companies, Rinse, tells its workers not to accept tips. It says that not thinking about tips improves the experience for the customer. Competitor Washio says on its website that "there is no need to tip." But Schweitzer says you should try anyway if the cleaned laundry is delivered to you and not left with a concierge or doorman.
Tip: 10 to 15 percent of laundry bill.