Issue: The ionic application stuck after restart or kill the application

hello guys,
I’m still newbie in ionic developement and now I’m working on with ionic and SQLite database. Anyone of members in this forum follow this tutorial ?

I already read and followed one by one code in this tutorial but I got some issue that I dont know how to fix it. The issue is first time my application launched at my android emulator is working 100%, but if I kill my application and come back again it just shows me “loading”. To make it run again, I need to clear up the data from app settings or reinstall. Same as the other tutorial I follow ( ) . So, anyone can help me to fix this problem ?