I am on a grandfathered Tuta plan that costs me about $2 CAD a month. I also pay for Proton’s premium plan. Both are worth it to me. I get that everybody has a budget but at the same time 10 Euros a year is a tight one when dealing with privacy friendly alternatives.
If we’re talking about mobile apps only then ntfy, Fluffy Chat, KDE Connect, Nextcloud, Tuta, Protonmail, Session, Conversations, Organic Maps, Fedilab, Mull, DAVx and KeePassDX.