Will WP 8.1 apps work on W10 TP?

I'm planning to upgrade my TP from WP 8 GDR 2 to WP 10. Will my apps from 8.1 still work on WP 10?

BTW I have a Lumia 535.

Thanks for the help. 😊

Probably not all of them. SimpiRSS and SBB Mobile (a Swiss Railways app) did not work for me. So be prepared for troubles.

Pretty much all of the apps I had work well, except for a few glitches