So as an experiment, we Checked In & Out of 12 Sites a day for a month. A lot more than any of your employees are likely to use. Our total data usage on a Smartphone for the month was under 50 mb. This was with moderate photo verifications usage which would be the largest contributor to higher data usage.
In comparison in the same month on that device.
Google Maps 135mB
Chrome 527mb
You Tube 244mb
Google Services 178mb (this is actually updates that just kept the phone operational)
Gmail 127mb
Facebook 94.10mb
Twitter 47.97mb
100's of Apps in between
freshOps 46.9 megabytes
Mobile Security 22.71mb
So you can see that if you have staff with Smartphones, the data to keep it running is more than the freshOps App.
Should you reimburse your staff for the data?
If we take Telstra as an example being one of the more expensive data providers.
On average most providers offer data for $10/GB
https://accan.org.au/hot-issues/963-excess-data-charges
1GigaByte Data costs $15/month
1GB is 1000mB
therefor 1mb of data costs $0.015
So freshOps would use $0.70/month of data of a Cleaners plan.
The choice is yours.