CrossOver

CrossOver is a free and open-source application built with Electron, and bits of JavaScript and HTML code that allows you to place an "always-on-top" crosshair overlay.

Intended primarily for gaming purposes, the app allows you to place a customizable crosshair to mark the center of the screen (or any other position of your choosing), thus allowing you to either gain a competitive advantage or generally improve your aim (for example, in games where various weapons don't offer the option of having a crosshair).

The app has bespoke Windows installers (as well as macOS and Linux installers), as well as a portable version. One of the main advantages of this particular crosshair app is the fact that it provides you with such a crosshair overlay that boasts a ton of configuration options.

Before we get in-depth about these options, it's also worth noting that the app comes with support for multiple monitors. Using the app could not be easier: simply use CTRL+ALT+SHIFT and arrow keys or the mouse to move the crosshair to a specific location on the screen.

CTRL+ALT+SHIFT+X allows you to lock the crosshair into place, while CTRL+ALT+SHIFT+R makes it easy for you to fully reset the crosshair to its default position in the center of the screen.

To start with, please note that the app provides you with over 50 crosshair models, including a dozen of dot-based ones. You can fully customize the crosshair's size, color, and opacity levels.

This will ensure that you always have the best vision of the crosshair, regardless of the game's environment, and it's also quite useful for gamers who suffer from colorblindness or have problems dealing with high levels of contrast.

Even though CrossOver is a seemingly simple app, it gets the job done rather well. It's easy to use, it offers numerous customization options, and it comes with over 50 crosshair types, making it one of the best apps of this sort out there, and, don't forget, it's free.