Here's a Pleco version of Taiwan Ministry of Education's Dictionary of Chinese Idioms. http://dict.idioms.moe.edu.tw) It is a monolingual Chinese dictionary. Data is from dict_idioms_2011_20151102 and dict_idioms_dif_2011_20151102, which are CC licensed, with only formatting added. One exception is that the simplified version of the headwords are not from the data files. I tried a couple of simplification tools and got different results for each, each with its own set of errors. It would require more work to get all the simplifications correct. I created two versions, one "short"' version with only the "main" entries, which excludes the variants. Another version has all entries. Personally, I like the shorter version because if you browse dictionary entries then they will all be "main" entries. Notes: 1. Some entries in the data file are blank. For example, there is an entry for 好事難諧 in the data file but there is no definition. If you search for that phrase on the web dictionary, there are no results. I've excluded those entries. 2. There are a lot of places where images were used in place of rare characters. I just replaced the image references to an unknown item symbol. Only one of those image characters appeared in a headword. 3. As a general reference, I also recommend the Duogongneng Chengyu Cidian. It probably puts the most effort into clearly spelling out the literal meaning of a chengyu. In English, the KEY dictionary is also good at defining the literal meaning. The strong point of the MoE dictionary is great depth for a subset of chengyu--not necessarily the most common ones but the ones that are common in books of chengyu. It is a great dictionary for reading and not just as reference. 5. If you look up an entry with ㄧ or possibly 不, you may see two pronunciations on the MoE website. For example, for 一成不變 you see the pronunciations yī chéng bù biàn（變）yì chéng bú biàn. In the data file, only the first pronunciation is included, with a first tone, so I just used that pronunciation. 6. On the MoE website, "main" entries are designated with a 主 symbol. (See the MoE website for more info on that.) That designation is not in the data file and I didn't know where I should include the symbol so it is not included in the Pleco version. 7. On the MoE website, the main footnoted part of the quote in the dianyuan section is in black text while some surrounding text is in gray. (See the MoE website for more info on that.) It would be nice to have that in Pleco but that was not marked in the data files so it's not included here. 8. The data provided by MoE has HTML tables provided for the 辨識 section. Those tables have been flattened. This section is pretty interesting so it might be nice if the entries that have a 辨識 section were marked in some way. 9. References to other chengyu are sometimes linkified, but I only did that for chengyu that are in the dictionary. 10. I haven't tried it on Android so I'm not sure if there will be any font problems there. 11. There is some info on the MoE website that you might find useful that was not included in the data files. For example, there are little chengyu stories which are long examples. 12. The data file did not include the line ends for each subsection, so those have been added back in, mostly reflecting the style as seen on the web version. Order of subsections is a little different than the web version.