This is a paid asset, but now you can download Grids 2D Free.
Detail this asset from Unity Store: Original Link
Grids 2d v6.4.2 (Latest version)
“If possible, please buy the package to support the developer”
Grids 2D is an easy to use, highly optimized and flexible grid generator and territory/cell highlighter/fader.
– Configurable, fully interactive and flexible grid generation, including Voronoi tessellation, boxed, rectangular and hexagonal types.
– Produces highly optimized grid mesh with reduced vertex count.
– Two levels of regions: cells and territories.
– Fastest selectable and highlighting system for both cells and territories.
– Coloring and fade out support for both cells and territories.
– Control the visibility of individual cells using API or alpha texture mask.
– Change visibility, color or texture of cells from Unity editor with the integrated grid editor.
– Define territories using the API, the grid editor or assigning a color texture
– A* Path Finding support. Get configurable paths from one cell to another with a single function call. Define blocking cells or specify crossing costs for entire cells or custom costs per hexagon side!
– Range function: get reachable cells within a given distance and a starting cell.
– Extensive API (C#) for controlling and managing the grid, including selectable cells/territories, finding neighbours and merging cells.
– 16 demo scenes included with practical examples (checkers board, texture/mosaic revealing, cell visibility, vertex locating, texturing, cell merging, masking, path finding, …).
– Works with orthographic and perspective cameras!
– Unity 5.5+, 2017, 2018 and 2019 support.
– Compatible with Standard/builtin and LWRP.
– Full source code included (C#).
Product Documentation | Support Forum | Youtube Channel
Check out also Terrain Grid System which supports 2D and also Unity terrain grids!
Even more cool assets!