While building apps for Apple (or Android) mobile devices can be a lucrative way to generate passive income online, it's not as easy as many people make it seem. Beside the fact that it’s hard to get your app noticed among the millions being released every year, most people expect apps to be either free or very inexpensive. In fact, a recent study found that only 11% of apps are paid for. The number of paid apps will only decline over time as more players join the market. The key, like many of the business model mentioned here, is to be strategic and creative from the very start. There are a few ways to monetize your app and keep it free for users. Examples include advertising, premium services, and sponsors.
Who cares? I don’t care one bit about building a “successful company” with most of my passive projects. That’s for my active projects — and I’ve done that when I converted them into active projects. For passive income, I can build products and automated services that are useful enough that people want to buy and use them. My Magento modules and Udemy course had 5 star ratings despite being passive. I knew back then that I could probably sell 2x as many copies of each if I made it my full time job — but I chose note to. I realized that if I could have more fun, get more fulfillment, and make more money out of other passive activities, and that’s why I don’t care that my passive businesses are small and nichey. Again, though, converting one of them into an active business has made it much more successful — so I would just remind you that they aren’t mutually exclusive, and if anything, having a Passive Income side business or 2 let’s you try out a few different waters before you dive in to any one.
When money is lent to a partnership or S-corporation acting as a pass-through entity (essentially a business that is designed to reduce the effects of double taxation) by that entity’s owner, the interest income on that loan to the portfolio income can qualify as passive income. As the IRS language reads: "Certain self-charged interest income or deductions may be treated as passive activity gross income or passive activity deductions if the loan proceeds are used in a passive activity."

All ideas take some amount of time and money to come to fruition. Some people have a lot of one of these, but not much of the other. A lot of successful ideas have started when one person had the resources that another did not. And many businesses have been started using 0% loans from credit cards to fund their concept and keep the business going until it achieved success.

Ebooks are one of my favorite sources of passive income. Now, you can do this the simple way and just publish it on Amazon's KDP. Or, you can go all out and build yourself a book funnel. Book funnels are powerful, but they won't be fully passive. For example, if you do a free-plus-shipping offer for your ebook (converting it into a physical book), you'll need to create some one-time offers (i.e. extra training) and up-sells (i.e. an audiobook). But, a book funnel can be very powerful.

Consider refinancing your mortgage if you haven’t done so in a while before interest rates go up further. Or consider leveraging cheap money responsibly to acquire hard assets. LendingTree Mortgage has one of the largest lending networks online, and they will contact you immediately with their offers. You want lenders competing for your business, and get hard quotes so you can pit them against each other.

If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.