Please clarify ;) the situation : - do you have a contract with developers ? - do you own the app ? or does it belong to the developers until you pay them ? - why are the developers asking payment ? - do you have a running app ? which needs does it covers ? - did you set a company ? - who are you...
It sounds like you need design with backend programming to accomplish this. If you are interested contact me directly to go over your tech. needs for this... Maybe Visit CodyL.com They are a team I am aware of that implement code with easy to use backend for clients own updates and build tools fo...
These are very good questions to start with. In addition, Make sure you cover the following bases: 1. Security - viruses are just one thing, ask them about pen testing done, system stability, fallback options, rollback plans for deployments/changes, make them reassure you that they are rock sol...