How to use Web Api for my application and which device I can use for this?

[Pulkit]

I have FitBit Alta and I want to have my steps/distance data in my app(not a fitbit app). I want to know how can i get data through API when my app is not active? Should I need to update my device or this device will help to get the data?

[Senorts]

Unfortunately there is no SDK for the Fitbit Alta at the moment. So you can't export that data.

[Pulkit]

Then which device should I use.Actually, I want my data in my own app.

[Pulkit]

I dont think you understood my question. May be i did not explain it in details. 

Here are more details about the flow that we are trying to implement:

We are thinking of using the Fitbit api to fetch user activity data in our backend. This we assume can be done if we have the user permission to fetch the data from the api using authorisation flow of the api. 

Now the question here is does all the devices of fitbit synchronize data with the backend of fitbit. 

[Gondwana]

All Fitbit devices make their data available via the Web API. However, this isn't real-time data; it is updated only when the watch syncs.

The data is kept on Fitbit's servers, so your app doesn't have to be running continuously to avoid missing data. It can just query the Web API whenever it starts.