Methods to ensure offline CRM usage!

Methods to ensure offline CRM usage!

Hi everyone. 

So my team is facing this problem - due to internet connectivity issues faced by some of our users, we're having to seek out alternatives for the CRM that work offline. 

The best solution to this we found was the Zoho CRM Mobile App. However, this comes with one drawback - the sensitivity of our data makes it very risky to allow the Data Entry personnel to download the contents of the CRM into their mobile App.

Ideally, we're looking for something that only allows Data Entry, and which works offline (but gets synced up to the online CRM was internet connection is re-established). Thanks in advance for any solutions!