Cosmigo Pro Motion NG vs Pixly

Tilemap can be drawn with tools that automatically keep your palette of tiles consistent. Both free painting and tile-placing modes work in the same workspace allowing you to easily switch between workflows.

You can separate the color information out of the image file into a separate palette file.

You can use Onion Skinning to see surrounding frames to help create animations.

The user can create normal rastered or custom grids with custom shapes, or they can just mix up all they want.

Pro Motion gives you a direct feel for the pixels: how they will lay down when pressed as soon as you've finished marquee selecting. It's thus very easy to drag around to get a perfect look, moving it a few pixels here or there.
Related to this then is the way you can play with single-color mode. You can drag-click the 'paste' to create different colored silhouettes of the selection. Even while zoomed in, you can see the exact pixels as they would be rendered if set down where your mouse is.

Oldschool pixel artists will find all their beloved functions from the Amiga Pixel Art Programs, DPaint and PPaint. Such functions include smear, paint, color cycle, mirror, kaleidoscope, tint, smooth, fill with dither or random dither, fill with spherical color fade, auto outline, and tons more.

Most keyboard shortcuts are the same as those of DPaint, so you immediately feel at home with ProMotion. You can of course re-define them as you wish.

If you want to create a simple 'masking', it's very simple. Most normal paint programs have transparency, but what they don't let you do is treat transparency as if it were another pixel on the screen.

Typically, you are required to set up layers, and use eraser to block/unblock areas to get the effect you want. This is both long-winded and uncomfortable.

Pro Motion supports the regular Layer System you would expect from Photoshop, but with the added support of animation layers (which have frames) and static image layers (for templates, backgrounds, or other static elements).

The user can copy any part of the frame or even whole animations and use them as brushes or just store them for easy re-use later.

You can easily create a mask to protect part of the image against modification, or to exclude part of the image from the brush capture action. The mask is created either by selecting the colors (from the palette or directly from the image), or by drawing it using any of the available tools (pencil, line, circle, box, etc.) Once defined, you can freeze the mask or let the program update it, based on the drawing colors.

Pro Motion gives you instant right-click access to the background color. This is useful in cases where pixels are very close to each other and you are not able to easily get the balance of each color right.

There is a free version available for Pro Motion that has a limited feature set but is a good way to check out the software. This is also a good choice for those who do not need many features but want to use a simple pixel editor. The limitations of the free version can be seen here.

There's a Gradient Tool with several modes of dithering.

RGB, CMY, HSB, and a somewhat different HUSL.

Pixly offers a color ramp generator that then exports directly into a custom palette.

You can work with a reference image on top of your art, or by its side.

This tool works on both phones and tablets that run Android, which is handy for when you do not have access to a PC.

In Pixly, you can move the art around with two fingers (like in Google Maps) and change the brush/eraser size with a three-finger pinch.

Onion skinning is also called ghosting. It allows the user to see the past and previous frames, while editing the current frame. This way, the user can make decisions on how to create or change an image.

In Pixly, the user can make symmetrical art with a mirror, or even go bananas setting up two or more mirrors at different angles at once.

The user can make transparent sprites in Pixly.

Even though this is a mobile tool, it's fully featured and even allows you to create animations.

The user can create tiles in Pixly and keep an eye on progress in real time.