meshmixer, Bryce, Terragen, World Machine, 3D-Coat, 3D Pixel Artist, Graphite, VoxelShop, VoxEdit, MagicaVoxel, PnP TerrainCreator, Geomorph, 3D Slash, VoxelMaker, Visual Nature Studio, Voxel Builder, L3DT, Goxel, SpriteStack, Outerra, World Construction Set, Cubik Studio, GeoControl, Slab.js, DreamScape, Voxelator, Grome, Project Vox, SpritePile, Raiseland, Curious Blocks, Slab6 are some alternatives to Acropora.