Make hardwareAccelerated = true
Edit Toast texts.
Improve the database stability (with aynsctasks) and now the status
won't be deleted but flagged after uploaded. (there is still  problem of
the UI thread being blocked, but it is unnoticeable)
Fix a bug: the welcome page activity will restart when the user click
the back button on other activities.
Improve the stability when swtiching between activities (based on the
previous commit) by creating the "loading page" activity as a starter of
the app; Finish the exit message/hint by using a custom toast