Some time ago I played around trying to measure the number of characters I know, mostly to track my own progress. If anyone else wants to try/play with the program I made, it’s at: tapani.homeftp.org/cgi-bin/hantrain.cgi
Please keep in mind that it is hard to measure this accurately from a limited number characters tested, so don’t take it too seriously
Agree that showing accented vowels would be nice (maybe in addition to a exponented tone number?). So far I am just using whatever pinyin was in the public domain dictionary I found.
Adding the tones programmatically might be tricky, since some syllables contain more than one vowel (like dian). Which vowel should get the accent? The first? The second? Depends on the syllable, and I need to add a table of them…?