Singpolyma

All I need is to prevent someone making commercial profit out of MY app!

If you want to inhibit big corporate exploitation, then copyleft is often enough. The situation is somewhat complicated because most copyleft licenses prevent an app from being put on the Apple appstore (because of Apple's terms). It would not prevent you from putting it on the appstore of course (unless you accept patches).

If you actually wish to prohibit commercial use of your app, you will find that such a prohibition is incompatible with the Open Source Definition: https://opensource.org/osd