Offline data sync - after close my app

Hi,

i am a newbie in ionic.
also my englisch is very wrong. I hope you understand my problem.

Is it possible to build a ionic offline app which can sync data after i have the app completed closed.
I have try it with couch - pouch DB but it doesn't work.

My workflow example:

1. I am offline
2. run my app
3. save data from app localy
4. close my app - IMPORTANT !!! full closing, for example iPhone double push Homebutton ....
5. now i am online
   6 ... ??? what is now?
   It will not sync.
   Is it somehow possible to sync data without start my app.

Do you understand my question?

Thanks for your help

Currently i use ionic with angular 4