Pixel Art Maker

[You Gotta be Joshing me]

I highly recommend using a PC running Windows/macOS/Linux as a mobile device such as an iPad is far less capable when compared to a PC.

I've heard some good apps for Pixel art on both web and iPad are:
Piskel
Lospec
Procreate
Pixel Studio

If you ever get a PC running Windows/macOS/Linux, I recommend checking out Asesprite, or its FOSS equivalent LibreSprite.

Hope this helps.