I’ll throw in another recommendation for Caddy. I’ve been using it for years and the few problems/feature suggestions I had got implemented by the developers pretty quickly. They’re super active on their forums and I haven’t yet run into an issue where I couldn’t either figure it out myself or with help from their community forums (usually from a dev.) They’re very friendly and won’t berate you for simple mistakes like other devs.

I’ve been using Fossify Calendar for a while now and it’s been pretty great. I moved to it after the whole Simple apps getting sold drama when it happened.