Edit: Before you read, I made some mistakes here that I mention in my part 2
My mobile operating system of choice is GrapheneOS. I run it on a used Google Pixel 8, as I didn't have enough money for any of the phones in the Google Pixel 9 lineup, which offer a more secure ultrasonic fingerprint scanner. I used to use iOS, but I finally managed to switch. I wanted to share my thoughts on GrapheneOS, problems I had, and the apps that I use.
To install apps, I first check if it is available on GrapheneOS's built in app store. If not, it is installed via Accrescent. Because Accrescent is still very small in support, most of my apps are installed via Obtainium. One app however, ProtonVPN, is installed via Aurora Store, because that is the only installation medium that allows me to sign in as a guest.
I do have a Proton account, so signing in isn't an issue, but since I plan to use ProtonVPN until I can pay for Mullvad VPN, I might as well get as much anonymity as I can. I don't use the actual Google Play Store, despite claims of it being more secure, mainly due to me required to create a Google account. I only use Aurora Store for ProtonVPN. For apps that are not available for Obtainium but are available on F-Droid, I simply use the F-Droid repo inside of Obtainium. All apps are verified with AppVerifier.
For games I have a very small selection. Simon Tatham's Portable Puzzle Collection is a game collection I have been using since before I even knew it was open source. Antimine is a Mines client, which is a classic. I also play a game called Zoysii, which is only available on F-Droid. It passes the time. Code Word is a nicely made Wordle app, with some extra features. Open Sudoku is a nice Sudoku app, however I found that almost all of the available puzzles to install are very easily solvable. 2048 by SecUSo is a decent app to play 2048 that is still maintained, however it currently does not have a dark mode theme. blichess is a fork of lichess that simply adds the option to play over Bluetooth, which I really like.
My mobile 2FA app is Aegis, which is really everything you would expect. Audire is an open source frontend for Shazam, which I use for music recognition. I'm sure there are some better apps with different APIs, but Shazam works really really well, and that is what I am looking for in the app. Aves is my photo manager, as it allows for proper photo hiding. It is available through Accrescent, which is nice. It is one of few apps that required me to sign terms and conditions, but it doesn't matter since it doesn't have internet access anyways. It allows me to view extensive details about photos, and even remove metadata in the app.
I use AndBible for Bible study, but the project seems to be abandoned and needs lots of improvements. I sincerely hope a good alternative is developed eventually. I would be willing to help out any way I can.
For messaging I use SimpleX Chat for my most personal chats, but for mostly everyone I contact them via Molly, which is a hardened version of Signal available on Accrescent. When I am offline, I contact nearby people through Briar over Bluetooth, which is awesome while camping. I don't have any cellular provider, so I occasionally have to make sacrifices in terms of contact.
The default GrapheneOS calculator has no dark mode, so I opt for OpenCalc as my default calculator. I tried both Etar and Fossify Calendar as a calendar, and have been much happier with Fossify Calendar. A lot of Fossify projects have been abandoned, sadly, so I may have to switch.
I use the default GrapheneOS camera for most of my pictures, but when I need high quality shots I will use Open Camera. It supports HDR and some post processing. The GrapheneOS camera has incredible support for code scanning, such as QR codes and bar codes. I don't plan to use the Pixel Camera, since those apps work just fine for me. To edit photos I use the GrapheneOS gallery, but it is somewhat lacking. I plan to stick with it as they add new features.
I have a ClearClipboard app that, simply, clears the clipboard when you open it. It's a small tool but I get very paranoid about clipboard access. I've found that my password manager doesn't reliably autoclear, which I will discuss later.
The default GrapheneOS clock app is fine. I wish there was an OLED theme, but it's worked for what I need. DeepL is what I use for translations, because I cannot seem to find an offline translator app. It's very upsetting. For my keyboard I use HeliBoard with the proprietary swipe to type module, and it's great. There are a few weird autocorrect suggestions, such as not recognizing the word "A", but it's honestly not been a huge issue.
I use Joplin to take notes. I had issues with Standard Notes when I was on iOS, and had switched to Joplin there. I now can't even imagine why anyone would even try to use Standard Notes, Joplin makes Standard Notes look like a joke. It has all (or at least all I care about) of the paid features of Standard Notes, for completely free.
My password manager is KeePassDX, which is honestly exactly what I would want from a password manager. The only issue I've had is that it sometimes disables biometric unlock and makes you unlock it yourself, which is super weird. Besides that, I will be using it until either it dies or I do.
For eBook reading I use Librera, but the UI is honestly atrocious. The best eBook reader I have ever used is Apple's stock Books app, and I honestly wish something of that polish existed on Android. Librera will work but it's not nice to use.
I have LibreTorrent in case I ever need to torrent something on the go. It's fine, I wish torrent software would include a hard toggle to disable seeding, but it's worked as intended. In a similar category I use LocalSend to transfer between any of my devices. I haven't tried KDE Connect because LocalSend has never caused me problems. The only issues I have encountered were because of strict VPN settings.
I eventually plan to use Mullvad VPN, but until I can afford it I am using ProtonVPN as I mentioned. I have no real comments because I have only used ProtonVPN. IVPN is on my radar, but Mullvad VPN is still at the top of my list. IVPN is available via Accrescent. I also have Orbot in case Proton or Mullvad are blocked.
Music players have been a struggle for me. All of them have their own various issues. All I really need is a nice way to play mp3 files offline and sort them into playlists. A night timer is nice. Vinyl Music Player is what I use for now, since Fossify Music Player seems to be abandoned. I'm open to some open source alternatives here, since the ones I have tried all have issues. Ideally these should be available by Obtainium.
I use Organic Maps for navigation. Support is alright in my city. OsmAnd has a pretty bad UI but it's gotten better. Organic Maps I've heard has a few issues, and OsmAnd has a premium tier, but I don't really care. I am just sticking with Organic Maps. I'm happy with it, so it's fine.
I have RadioDroid installed to try it out. It lets you listen to radio stations over WiFi. I'm jealous of Motorola users for their built in AM/FM radio receiver antenna. I might not keep this app, since it's fairly useless when you think about it. Either way, maybe a GrapheneOS phone will come along with a built in antenna.
I have Tor Browser installed just in case I ever need to visit an Onion site or use a Gecko based browser. My main browser is Vanadium, and I did try Mull but it doesn't block advertising redirects even with uBlock Origin. Vanadium is fine for now.
I have Trail Sense as a compass and emergency survival app. I hope I never have to use it for survival, but at the same time, I hope this app saves my life. It's cool to see how many sensors it utilizes to help you out.
Tubular is a fork of NewPipe that has SponsorBlock support. I like it, it's not as polished as I would want but it's plenty usable. I wish it had DeArrow as well, but I'm sure it won't be long until it's added.
I use the Fossify Voice Recorder for voice recordings. It's what you would expect, not much to say here. For weather, I use Breezy Weather. For some reason some features were unavailable on the F-Droid version, but after installing with Obtainium I now have plenty of features at my disposal. It's almost as good as the iOS weather app, and has plenty more features. The accuracy where I am is slightly iffy, but it's good enough that I can rely on it.
I use a passphrase to lock my phone, and use biometric unlocking to ensure no one can shouldersurf passcodes. GrapheneOS only lets you add up to 4 fingerprints, which is a good enough limit, but I do wish it was higher. If I wanted only 4 fingerprints, I would choose that myself. I backup GrapheneOS using my own USB stick and the built in backup option. Some apps such as SimpleX refuse to be backed up automatically, but I can simply manually export the database and backup that file.
Even without any Google frameworks installed, GrapheneOS has been a really seamless and polished experience. The issues I would raise are actually with Android itself, such as weird management of app signing, but overall GrapheneOS has been incredible. GrapheneOS is honestly the minimum every person should expect in terms of privacy and security on their phones, because nothing else even comes close to GrapheneOS in those categories. The gap between iOS and GrapheneOS is absolutely massive, given that so many of the apps I use are Android specific.
LibreTube uses Piped instead of Invidious. I tried LibreTube, but some subscription videos don't show up because of an upstream bug with Piped. I am continuing to use Tubular (a fork of NewPipe that adds SponsorBlock) until either the Piped bug gets fixed or until NewPipe finishes rewriting their code.