Not related to polyominos, but I like House of Graphs: https://houseofgraphs.org
It allows you to search by graph6 code, so if you find an interesting graph, you can check whether that graph has arisen in other contexts.
Not related to polyominos, but I like House of Graphs: https://houseofgraphs.org
It allows you to search by graph6 code, so if you find an interesting graph, you can check whether that graph has arisen in other contexts.