Following my switch to [microG](https://microg.org/) (an open source re-implementation of Google Play), some Google Apps stopped working ({% post_link microg-google-play-replacement 'read here' %}). During my search for replacements, I discover many open source alternatives. These are the apps I'm currently using and recommend to everyone.
Aside from below list, check out the NanoDroid's [list](https://gitlab.com/Nanolx/NanoDroid/blob/master/doc/Applications.md) of other great open source alternatives.
[F-Droid](https://f-droid.org/) + [Yalp Store](https://github.com/yeriomin/YalpStore) | Play Store | Compatible with microG. F-Droid is an app store for open source apps. Yalp Store is to browse and install apps listed in Google Play *without* a Google account.
[Fennec F-Droid](https://f-droid.org/en/packages/org.mozilla.fennec_fdroid/) | Firefox | It's an official build by Mozilla for F-Droid with less proprietary components (Google Services Framework?). Particularly suitable for [microG](https://microg.org/).
[Simple Calendar](https://github.com/SimpleMobileTools/Simple-Calendar) + [DAVx⁵](https://www.davx5.com/) | Google Calendar | Google Calendar doesn't work with microG. It's part of [Simple Mobile Tools](https://simplemobiletools.github.io/), so it's open source and include dark theme. Use DAVx⁵ to sync calendar and contact. Google uses proprietary protocols instead of CalDAV and CardDAV, so data migration is required.
[Simple Gallery](https://github.com/SimpleMobileTools/Simple-Gallery) | Google Photos | The only reason I use Google Photos is the ability to view panoramas, despite having no issue with microG. Since Simple Gallery is part of Simple Mobile Tools and supports panoramas, I gladly switched.
[uNote](https://gitlab.com/Varlorg/uNote) | OI Notepad | Smallest (71KB) open source notepad app that I could find.
[KeePass DX](https://www.keepassdx.com/) | [KeePassDroid](http://www.keepassdroid.com/) | Utilise Material theme so it looks more modern and feels lighter.
[Lithium](https://play.google.com/store/apps/details?id=com.faultexception.reader&hl=en) | FBReader | Free but proprietary EPUB reader. The best feature is read by scrolling; each chapter is displayed as a long text and you scroll down as you read. I find this feature faster than flip-by-swipe and without the accidental touch issue of flip-by-tap.
[Unit Converter Ultimate](https://github.com/physphil/UnitConverterUltimate) | | The only unit converter app that you would ever need. Supports every practically possible units including currency.
[Loyalty Card Keychain](https://f-droid.org/packages/protect.card_locker/) | Google Pay | Simply to store loyalty cards with barcode.
[HERE WeGo](https://play.google.com/store/apps/details?id=com.here.app.maps&hl=en) | Google Maps | I use it simply for compatibility microG (which Google Maps doesn't work with). Maybe I'll consider [OsmAnd](https://github.com/osmandapp) or [MAPS.ME](https://github.com/mapsme/omim) which are open source and utilise [OpenStreetMap](https://www.openstreetmap.org/).
