This is perhaps the most flexible job you will ever come across as you can literally teach anything, anywhere at any time without any experience or qualifications required! You will have the flexibility to set your own schedule in advance and work directly via your smartphone or tablet.
Languages, in particular, are in hot demand. Popular languages include Arabic, Bahasa, Malay, French, German, Hindi, Italian, Japanese, Korean, Mandarin, Portuguese, Russian & Spanish. If you are confident in teaching additional subjects such as school & uni subjects, or even lifestyle subjects such as fashion, fitness, health & music, you're welcome to do so.