Chatty (https://chatty.wastu.net/ by B. Wastu: https://github.com/bgwastu) accompanies the improvement of a text with suggestions for spelling/grammar correction and advice on style or rewording. The text can be corrected and then proposed again.

In EN but accepts French if specified (see screenshot).

Tests from the incipit of ” Du côté de chez Swann ” by M. Proust and from a student’s copy on Eduscol: http://cache.media.education.gouv.fr/file/Francais/68/1/EV16_C2_Francais_evaluation-copie-texte_lien5_748681.pdf

No accounts and unlimited.