Where can host my website or application for free

Generally speaking, free hosting is worth exactly what you pay for it, possibly less. reliability is normally low, DB counts and sizes are tiny, up time is normally short, technical support is non-existent or very expensive. Some will also implant advertising in your site for which they will get revenue, not you.
All of which is very understandable: it costs money to provide these things, so your free site will always get a lower priority.

I'd strongly recommend that you look round for a cheap(ish) hosting service that provides what you want, and has reasonable charges - you will almost certainly get a better product.