It’s a pleasure to hear that you enjoy our app. Thanks a bunch for your awesome feedback!
Regarding your suggestions, currently there is no way to do this, unfortunately. We already have a request for the multiple services feature. Feel free to support this idea - Add multiple services.
As for the custom Sender Name and Subject, I’ve added this idea to the Wishlist too - Add an option to set a custom Sender Name and Subject.
Let me know if you have any questions left 