Hi,
As per your description, I could see many aspects:
1. I would first like to see the CRM and membership management software for the fitness industry to get to know what exactly an app could do.
2. Secondly, I must need the API of your CRM in the form of JSON so that this app can be developed. IF you don't think it's possible from your end then you must provide the source code of the CRM system where my developers will do the needful.
3. We are flexible to us ionic framework but the budget you have mentioned is too low to be agreed upon.
Lets see the CRM first ad finalize the modules, after that I shall quote it officially for you.
Regards,
Mit-