Is 10ten Japanese Reader (Rikaichamp) safe?

Looks up Japanese words on text pages with dictionary popups and reading support.

This extension lets you activate Japanese lookup from the toolbar or with Alt+R on text pages. It recognizes many grammatical forms and character variants, shows pitch accent and kanji information, and converts items such as Japanese numbers, yen amounts, era years, room measurements, and shogi moves. It includes settings, automatic dictionary updates, and localization in English, Simplified Chinese, and Japanese.