errors running zoho creator native app on iphone6

errors running zoho creator native app on iphone6

We have written an app that required users offsite to use, and therefore need to implement a robust mobile platform.  Problem so far is we are having different errors appear over various platforms. Is there a known issue with the zoho creator native app running on iphone vs android vs mobile browser ?
Also, what is the most reliable mobile browser to use on either apple/android if we wanted to run the application via mobile browser rather than the zoho app ?
Getting very frustrated with inconsistencies between app vs browser, apple vs android !!!
At this present time, we are finding :
--  running the app on iphone6 is sketchy, it crashes out regulalry, cannot return rows on queries to the database at certain times.  
-- The android devices running the app appear more robust but there is a huge delay when adding/updating records and refreshing the screen.  
-- Using safari or chrome on iPhone6 seems very robust, however the tradeoff here is that the screen is not as user friendly, drop down lookups are small and fiddly, overall appearance not as good as the native app. 

Any ideas/suggestions very welcome
Jennine