While our in-app SDKs for iOS and Android do not directly contain functions to execute subscription / recurring payments, you can achieve this through your service layer or backend servers.
In order to execute a recurring payment / subscription payment you would need to store the token (i.e. the token for the credit card stored in our vault) in your backend databases first.
The token is generated when you call the ObtainToken functions in either SDK.
Once the token is available in your backend databases then you can use our XML API to issue recurring / subscription payment requests.
Note that our tokens are reusable across the Mobile SDKs and our Web / Ecommerce APIs.
Please refer to this article on how to reuse the tokens: