SubWallet does support XCM (cross-chain) transfer. Below is an example of XCM transfer with SubWallet mobile:
Step 1: Click the Send button on your home screen.
Step 2: In the Send section, please choose your sending account, input the receiving account address, and the chain you want to transfer from and to. Then click Continue.
The above display applies when you start the action from the All accounts mode.
If you start from a single-account mode, the wallet would automatically fill in the from account section with the address of the account you are currently in. You would not have to manually select a sending account.
To see if you are in the All accounts mode or a single-account mode, please look at the account name on top of the home screen:
The following example is a cross-chain transfer between Astar and Acala network:
Step 3: Input the amount you want to transfer and click Continue.
Step 4: Review transaction and click Send.
Step 5: Type your password and confirm the transaction.