This is a gathering of websites that are interesting and useful.

The list is in alphabetical order and could be updated from time to time.

amCharts

The website provides a set of visualization tools, including an online chart editor and an online map generator. These applications are free and fully-functional. The free image has a website logo that can be removed by paying for a license.

But the most powerful tool from amCharts is its libraries for plugging interactive visualizations into a webpage. One can write a relatively simple JavaScript/JSON file (or TypeScript, which I am not familiar with) to generate a fancy complex image, such as chord diagrams, sankey diagrams, and annotated world maps.

The only inconvenient part is that the library is a little bit heavy if one only wants to make figures for a paper or presentation. The library does provide an export function, but requires some manual operations.

COCA, Linggle and Netspeak

These are websites for improving English usage/writing by checking/finding the proper combination of words, i.e. phrases.

For example, on Linggle, one can find the best combination of words that looks native to English,

1. * for filling in a blank of a phrase with multiple words.
2. _ for filling in a blank of a phrase with one word.
3. ?word for checking if word is needed in the phrase.
4. word1/word2 for choosing the best word from word1 and word2 for the phrase.
5. pos. for finding a word of the specified part of speech for the phrase. pos. can be v., n., adj., prop., det., conj., pron.

COCA and Netspeak are other two websites for the similar purpose, and its usage is self-explanatory from the website instruction.

Wordart

The website is for generating a cloud of words, e.g. keywords of a research project. The resulting image can be highly-customized. One has to pay for high resolution image. However, I think the resolution of the free version is high enough for regular usage.