Shuddhoshabdo is Bangla spelling service. It checks Bangla spelling during typing in any websites. This extension works with all chromium based browser. 
Shuddhoshabdo bangla spellchecker in existance since 2005.  shuddhoshabdo add-in for Microsoft word still used by thousands of users. This is the only Bangla spellchecker which is used by professional industry such as book publishers and news papers. 
This service will be free as described conditions in shuddhoshabdo.com license agreement.
This service only checks Bangla Unicode text. 
It follows standard Bangla spelling policy compatible with Bangla Academy of Bangladesh and Paschimbanga Bangla Akademi.