As a course developer and promoter, I can say that on the face of of it, promoting can be easier than developing one. The upside of development though, is that once it’s done, have to do is keep it updated and it can earn you money for years. That’s the case with my SEO copywriter training course, which I’ve been teaching (and earning from) since 2009.
Actually Nunya, Jafar’s English is very good, with only a few very minor errors, and far better than most English speakers. It is simply not true that you can “barely read it”, it’s as good as yours. Most Americans, Australians and British I see online have very poor spelling and grammar, and use memorized abbreviations and SMS-speak instead wherever possible. You cannot sound as if you have something to teach people, if it sounds as if you still have to learn basic literacy yourself!
If you have a good idea for an app, and the skills to create it, then producing your own premium app can be profitable. However, with so many free apps available, it may be hard to convince people to pay. If you want to go down the premium app route, consider having a basic free version to encourage people to download the app in the first place. You can then provide the option of upgrading to a premium plan once users realize how useful the app is.
There are also shopping apps like ibotta, MobiSave, and checkout 21 that give you money back for shopping. And the Walmart app has a savings catcher feature where you take a picture of the barcode or upc at the bottom of your receipt and they search all surrounding store and if a lower price is found they give you the difference back. I have made about 50 bucks total from this app and 20-30 from things like ibotta.
These aren’t the only ways teens can make money online. If you explore other options, proceed with caution. Read user reviews before signing up for any website to avoid getting caught up in scams. At best, those are a waste of time. At worst, they can cost you money and put you at risk for identity theft. If you aren’t sure a site is legitimate, stick to the basic rule of thumb: If it sounds too good to be true — like the employer that doesn’t ask to see a resume but offers to hire you on the spot — it probably is.