Partial Reference:
Youtube:
post by Filip Vujovic https://www.youtube.com/watch?v=fn5OlqQuOCk&t=19s
post by Android Coding https://www.youtube.com/watch?v=boyyLhXAZAQ
post by Vlad Voytenko https://www.youtube.com/watch?v=6EEk7ZW_A5w
post by TVAC Studio https://www.youtube.com/watch?v=hoF5A30fbu4 https://www.youtube.com/watch?time_continue=484&v=sTk7q3f-t0I&feature=emb_logo
posted by Tech1st https://www.youtube.com/watch?v=YlMDuFgf4I8
posted by Android Studio https://www.youtube.com/watch?v=p7BVdP0ljWo
Stackoverflow:
posted by jayesh https://stackoverflow.com/users/816614/jayesh answered by: https://stackoverflow.com/questions/6487509/findviewbyid-returns-null-for-edittext
posted by Droid https://stackoverflow.com/users/400923/droid answered by: https://stackoverflow.com/questions/3328757/how-to-click-or-tap-on-a-textview-text
posted by Ivan Aldwin A. Cristobal https://stackoverflow.com/users/8569218/ivan-aldwin-a-cristobal https://stackoverflow.com/questions/49595617/android-attempt-to-invoke-virtual-method-void-android-widget-textview-settext
Posted by Sagar Atalatti https://stackoverflow.com/users/5375019/sagar-atalatti answered by: https://stackoverflow.com/questions/34498147/location-getlatitude-on-a-null-object-reference
posted by Ben Walker https://stackoverflow.com/users/1098668/ben-walker answered by https://stackoverflow.com/questions/16879443/change-button-text-in-code-for-android-app
posted by Dijo David https://stackoverflow.com/users/395959/dijo-david answered by https://stackoverflow.com/questions/4384890/how-to-disable-an-android-button
posted by Makoto https://stackoverflow.com/users/3867750/makoto https://stackoverflow.com/questions/27261670/convert-string-to-latlng/33875637
posted by D.Grosso https://stackoverflow.com/users/5626006/d-grosso https://stackoverflow.com/questions/49467232/java-convert-location-coordinates-into-double-for-long-and-lat Google Developers: Manage Users in Firebase https://firebase.google.com/docs/auth/web/manage-users Read and Write Data on Android https://firebase.google.com/docs/database/android/read-and-write