Recycle items at the local recycling center if they accept collections. Many recycling sites will pay a small fee per pound of recyclable items. Go around your neighborhood collecting things like glass bottles, soda cans, newspapers, cereal boxes, and milk jugs. Have your parents drive you to the nearest recycling center and turn in your haul in exchange for money.
Drop shipping is another great ‘hands-off’ way to sell products. Firstly you will need to find businesses that sell products in your niche that offer a drop shipping service. Then you will need to create a website promoting and selling the products. When you make a sale, you take the payment on your site and then the manufacturer ships the goods to the buyer. The profit comes from charging a higher rate than the manufacturer, and if you are selling a high number of products this can quickly add up to a healthy revenue.
You can sell your ebooks through Amazon's Kindle program or Apple's iTunes Connect, which gives you access to a large majority of the digital-book reading market and the barriers for entry are incredibly low. You don't need to invest lots of money to make this happen, but you do need to invest lots of time, not only in writing the ebooks, but in marketing them as well.
However, like anything else truly worthwhile, apps require a significant investment of your time or money upfront. If you don't have the skills, then you have to hire someone who can assist you in creating a great app. But first you need to come up with an idea that will sell. Do the proper market research and analytics to come up with the right app.