Camera - OpenCamera. Surprised there's been no mention of this so far. OpenCamera offers quite a few pro features like RAW capture, customisable exposure bracketing/HDR, noise reduction etc.

Camera: GrapheneOS's camera app. Have been my camera of choice ever since I've discovered it. Never had an issue, offers all the basic features you would expect from a camera

Meta: just making sure that anyone that reads this comment is aware of the existence of Obtainium!

Obtainium allows you to install and update Apps directly from their releases pages, and receive notifications when new releases are made available.

Calendar

Etar https://github.com/Etar-Group/Etar-Calendar

Calculator: I'm using the one that came with grapheneos, which I think is the AOSP calculator. It meets all of my simple calculator needs

Camera: GrapheneOS camera for qr codes and videos, because the modded gcam app (not FOSS) I use doesn't support either. I like that it shows you the qr link after you scan it instead of instantly opening it. It doesn't connect to WiFi if you scan one though it will show you the name and password.

Calendar: Fossify Calendar. It's a fork of simple calendar. It has my favorite calendar interface and works with Davx5 to sync with CalDAV servers.

I use Calculator++pretty good scientific calculator app. For camera I use Open Camera pretty lightweight and have all features that I want. I didn't use any Calendar app. So, I can't suggest any calendar app.

Calculator:

• desktop: Speedcrunch
• mobile: Unitto

Speedcrunch is so nice I never explored alternatives. On mobile, I tried a bunch after posting to Lemmy, and while a lot of them are very similar, this was my favorite.

Camera:

• mobile: I use the built in app, but also keep GrapheneOS Secure Camera installed

Calendar: 🤷

Any calculator app that's similar to Numi on Mac (https://numi.app/) for Android or Windows? I like the running history and simple conversions.

I use num++ from fdroid because it's the only one I found able to represent expressions in "richtext" instead that a plain text line of numbers, because it is much easier to double check for errors

My suggestions.

Calculator:

OpenCalc - Very simple calculator, just how I like.

Calendar:

Shiftcal - Is a very, very simple calendar. I use it because serve my needs, and I just need a calendar to see future days.

Camera:

Graphene OS Camera - Im using this because I know is from Graphene and I know how their respect privacy. Has QRCode too.

Calculator: Unitto, also functions as a unit, date and time zone convertor. Very useful

Camera: Don't know

Calendar: Fossify. I have tried etar in the past but didin't like it (can't remember why)

Calculator++ has been my favorite so far. Previously I had been using either the google packaged or an open source that had widget functionality, but++ opens as widget size and they buttons are actually reoaponsive at that size.

Libre Camera is what I switched to after simple got sold. I don't use the camera app enough to really have an opinion. My biggest complaint is that my bottom row of essential apps no longer have the same design style or coloring.

Still using simple calendar. Probably going to wait until the fork comes out and switch to that, or may just use proton's calendar. I remember I didn't like theirs. Possibly because it either didn't have a widget or I didn't like their widget. I don't remember which.

Do FOSS camera apps (on Android) support "live pictures" - the type with several frames from which to choose your favorite? I really like that feature in Google's camera app. I do wish I could figure out how to export them as GIFs or something.