Monal isn't as stable with its encryption and notification as conversations for Android yet. And lacking reactions.
Generally the ios sector is underfunded/understaffed for xmpp devs. It has a much smaller privacy concerned // foss loving user group and a more hostile developing area for devs.

@menel @sbb thats not true, encryption and notifications work pretty well. No reactions yet, we are in the process of rewriting our chat ui to make reactions possible, though :)