We frequently get the question, "I'm very interested in switching to the Ghost Phone but I use (name any random app) regularly and am curious if it will work on the device?"
Unfortunately, our team does not have the resources these days to hunt down the answer to every specific app that people throw our way, and so our hope is that by arming you with the knowledge and information below you can hopefully answer this question for yourself faster than we can!
It is important to understand that if there is an Android app available, then the answer is yes, the app will work on the Ghost Phone... which is really just a Pixel phone running the open source GrapheneOS operating system, which is based on the open source Android mobile operating system framework.
On the Ghost Phone, and in GrapheneOS, you have the option of installing and using a sandboxed version of Google Play Services which will allow for any app that requires Google Play Services to function just fine. A number of our customers do this for specific work related apps they need to use daily or weekly. We walk through how to set up Google Play services on the Ghost Phone in detail at the very bottom of our "Getting Started Guide". Hence, as mentioned above, the answer is yes, all Android apps will work.
The real questions you need to be asking yourself are thus not if the app will work but:
1) Is there an Android app available? Can I find it on the Google Play Store or via F-Droid or does the company that makes the app offer a .apk that I can download directly from their website?
2) Do I even NEED an app downloaded on my device or can I simply login/access/use whatever it is I'm trying to use from a web browser interface?
3) Am I comfortable with the data/permissions the app requires I provide it in order for it to function on my phone?
4) If the app requires Google Play Services to function (fewer and fewer apps do these days, but some banking apps and games do) do I really NEED this app on my phone or is there an alternative I can find that accomplishes the same thing that does not require Google Play Services? (Interesting to note, many apps may say they require Google Play Services to function, however, once installed you'll find in fact they work just fine without it. The "requirement" is really because the Google Play Services component helps the app track more of your data on the device and sends it back to the company managing the app and Google! You won't know for sure if it will work w/out Google Play Services until you have the phone and give it a try). To see if there's an alternative, go to F-Droid.org or simply ask in any search engine, "Is there an open source alterntive to __ app?" and see what comes up. You're likely not the only person who's had the question!
Hopefully this helps add some clarity, answers and color to the question. If you STILL have questions after having looked through the information above, please don't hesitate to reach out to support@mark37.com and we'll try to get back to you as quickly as possible.