Need Offline method in my loan collection app - Need to work on offline mode also, Now it's working only online mode.

Need Android App Developer - For Offline mode enhancement process on existing android app

We have one collection app for the purpose of collection entry in field officer,
Need to work on offline mode also, Now it's working online mode only.
Sometimes when we go to rural areas it'll not work on the online entry process.
So, we need to work with offline mode also.

skills: java script angular js, Mysql-DB Java API Services