AFAIK there is one for Android called “MFSF Mobile Companion App”. Tbh i am not to clear about the costs for the full version. It seems its round about 5€ which would be really ok.
I am looking for a deck stream to control things like AP. At de.flightsim.to it seems that the mobile companion is somehow restricted to only some aircraft.
https://de.flightsim.to/file/2828/msfs-mobile-companion-app
Are there other apps or projects and what are your experiences with them?
Or is it better to buy the hardware from Elgato which is quite expensive.
Is this the same mobile companion as above?
https://www.reddit.com/r/MicrosoftFlightSim/comments/jnzouz/msfs_mobile_companion_app_map_nav_ap_and_more_new/?utm_source=share&utm_medium=mweb
Since i am new to this special topic its a little bit confusing. Thx for your efforts 
P.S. I know there are some thread that are a little bit similar but this is more general