For example of profit, the user of your app would have to tell you what coin they are mining.  You could then use the hash rate from the API and data from some exchange, whattomine, etc to calculate estimate profit.  There might be a possibility for your app to guess at what coin is being mined via the wallet/pool settings w/o having to have your user manually enter what coin they are mining. 

If you wanted to take it a step further, you could use the reported wattage and give an estimated profit taking that into consideration.