All right, so, quick and sloppy answer for the asker because there ARE alternatives to apple and android and they're pretty decent imo but ymmv.
I’m going to link you to two different operating system real quick, and then I’m going to list a bunch of apps I use that are alternatives to commercial and Google ones. Even if you don’t want to install a different OS (totally fair), you can still de-google your life a little bit by using different apps where possible!
This whole post assumes you have, if nothing else, opened and clicked around your phone’s settings at least once in your life. It doesn’t expect you to have arcane technical knowledge. Also you’re free to hmu if you have questions!
Alternative Operating Systems:
The two OS for smartphones I personally have experience with are LineageOS and GrapheneOS. The latter is best for Google Pixel phones, the former supports an eclectic selection of smartphones. Go through the supported models list on the website and see if anything suits you. They’re both Android-based and the interfaces will be familiar to Android users.
I don't have the spoons to get into how to install a different OS on your phone quite now, and it's been a long time since I've done it myself, but it's not too hard if you follow the instructions precisely AND make sure the phone you want to install it on has the requirements needed. For older phones especially, you might need to install a newer android version on them before you can put the OS on, so- make sure you have the right specs. You will void your guarantee if you put a different OS on your phone, so don't brick it.
But it's not arcane knowledge and at least the LineageOS website has very precise instructions and troubleshooting on it.
One downside of using a community made, user-built OS is that sometimes there's only One Guy still writing system updates for your specific phone, and if that guy stops then you no longer get updates. However, most android phones don't really have better or longer support from the get-go either, because the phone producer wants you to buy a new one. So, eh.
Also, your shit is not getting backup-ed into an Apple or Google account, which means you need to do this on your own, either manually or by setting something up in your home network. Getting into the habit of moving all your photos to your laptop every other month or so will save you a lot of grief.
You can salvage your shit if your screen is busted but your phone still works, but it will be more of a hassle than it would be if you had all your shit up in the Google cloud.
So if you really, really need specific apps that might require google services, you can install 'Micro G Apps' with your LineageOS installation. It's a smaller, better contained version of the google services that come preinstalled on commercial Android phones. If you have those, you should be able to run basically any apps you want. You can forego it completely and have an entirely Google-free phone, but some apps might not run (I couldn't get Pokemon Go to run because it couldn't load its maps on my phone - apparently it gets its maps from google).
That said, there are plenty of pretty good alternatives to some of your everyday use Apps:
- F-Droid: App Store for open-source apps only. I recommend this as your primary App Store, and it comes preinstalled in LineageOS.
- Aurora Store: A Google Play Store wrapper that allows you to download anything out of the Google Play Store without needing a Google Account. If you have Micro G Apps installed, you should be able to download and run commercial apps like WhatsApp from here, should you need those. Or like, your banking app >.>
You can download the Aurora Store from F-Droid, by the way. Otherwise get the APK from the website I linked. You will need to give it permission to install and manage apps, this is off by default. It’s in your phone’s app settings somewhere, but they move it with every Android version so idk where exactly. It’s not usually too arcane to find.
- Firefox is available on Android and you can install an ad-blocker on it. There's other options but honestly unless your phone is old as fuck and slow as fuck (… like mine) just get firefox.
Also… many things that you can get an app for you can also just do in your browser.
- I also use DuckDuckGo as my default search engine, personally. Takes some getting used to but has gotten p decent for anything that isn't Breaking News.
- Organic Maps is my go-to recommendation for maps and navigation. It uses the OpenStreetMaps Data, not the Google Data, so the information on it will be slightly different from Google, but OSM Maps have become really good especially in urban areas, and are often still better than the Google Maps in rural areas.
One of the big upsides (to me) of Organic Maps is that you have to download the maps to your phone, which means you have your maps saved locally even if you run out of Data, or don't have reception. You have navigation even if the network is dead.
Downside is you need to remember to download your maps before you go, if your data plan is shit (like mine :p).
Also it's non-commercial so you don't get sponsored recommendations.If you like sponsored recommendations, try maps.me instead.
- Offi is my go-to for public transit maps, trip planning, network plans, etc. Everything public transit. It's fantastic in Europe, I can't speak for other parts of the world but it seems to have most major cities of the world in it.
- NewPipe is my preferred YouTube Player. All the content, none of the ads, decent search system. Allows you to play videos in the background, or only play the audio, and apparently supports Bandcamp, so it's decent for music too.
- … I'm sure there's a Spotify Wrapper App out there too but I don't use my phone for music so no recommendations here. If anyone has anything feel free to add it.
- I think most of you have heard of Signal by now. It's not my favorite messenger but it's one your geriatric grandma and your annoying boss have a good chance to actually use, and it's open-source-ish and end-to-end encrypted. Beats WhatsApp.
It also does perfectly good audio calls.
- I also use Element, which is a client for Matrix, a federated chat and call system. I like it but if you're not friends with a lot of nerds you will probably not get your friends to switch to this one.
Look, I'll be honest, I don't use my phone for a lot of things other than the above, so that's it from me. For things like writing, reading, accounting, period-tracking, fitness, password manager, etc there's definitely a nice app out there for you, you'll have to dig around F-Droid to see what you can find. For gaming you might be out of luck if you want it ad-free and google-free (unless you like the classics, there's a million sudoku/bombs/solitaire/snake/etc apps out there. Also minetest, lol).
All the Standard Shit will come preinstalled in LineageOS, so like, image gallery, camera app, phone and SMS apps, pdf reader, etc etc.
For Commercial Shit - which is often inescapable in the modern world - like your bank’s 2fa, your public transit ticketing app, whatever, get your provider’s app through the Aurora Store. But I’m with @ms-demeanor here, the less shit you have on your phone, the better >.>
I do recommend just Trying Things Out, I installed a dozen accounting apps on my phone until I found one I liked and then just deleted the rest. F-Droid has a handy little list of the permissions apps want from you, as well as a list of ‘anti-features’ for things they consider negative (excessive data storage, non-free assets, commercial features).