proTile Map Editor 2.6 is a great tool for building various maps for your games and now with runtime support you can make building games.
Features
– Different brushes – mass placement, all snap, paint.
– Objects of any size – snap any tiles anywhere.
– Runtime support – Create runtime building games, full API for customisation.
– Tile-Connections – connect roads, walls and similar automatically.
– Custom Patterns – build once, place multiple times.
– Performance and size optimizations – combines meshes, reduces size for you.
– Layers – will help you to manage your maps.
– Tile Picker – filter / pick tiles right in the scene with (RMB/LMB + F).
– Easy to load and use – load maps in the editor, at runtime or stream dynamically.
– Procedural support – generate maps from code.
– Tile randomizer – Auto tile and rotation randomization.
– Different camera setups – Fits different 3D/2D type of games.
– Export to OBJ – Export Map or anything in the scene to OBJ.
– Custom Pivots / Snaps – Setup Custom Pivot size, snap size via component.
– Terrain & 360 snap support – currently in alpha.
– Editor for easy tile setup – categorise your tiles.
– Tiles & Examples – All Tiles & Examples from screenshots & Videos are included.
– Grids – 2D, 3D grid support.
– All platform support.
– Open source, examples, documentation and much more!
Full Unity 2017 and 2018 support
Original_Link: https://assetstore.unity.com/packages/tools/level-design/protile-map-editor-2-6-runtime-support-11698