Welp, it's official, the 3DR Solo app is dead. I received an email from 3DR stating: "The SOLO has been discontinued there will be no more updates, we recommend you to downgrade to the previous version [of Android] to resolve this issue."
Same problem here! Tried to fly the drone this weekend to take pictures of the fall colors. The camera is useless without the app, so I couldn't fly it and take pictures. App won't even open on Android 9 Pie. It just immediately crashes!