Hello mes ami!
I am back with a new question. Does anyone know how to change recall day for a group of cards? I have created almost 400 cards, and the only way I know at the moment to set recall days is to go through them individually. But there must be some other way, mustn’t be? Please, experts in the field, I am looking forward to hearing from you. 
AnkiMobile doesn’t currently support doing this in bulk, so the fastest way to do it would be to sync your cards to the computer version, and reschedule them there.
Thank you my friend !