Gmail Apps that support multiple senders

are there any Gmail apps that support multiple sender addresses?

NOT the default mail app on iOS

the problem with the default Mail app is that your sent items are not saved in Gmail's sent inbox, and the sent emails with attachments do not show with an attachment icon in gmail's inboxes
if you, like me, use Gmail heavily as your primary emailing tool, you would understand all these problems I'm having

and to be able to switch between senders
I've been having to do it with workarounds (such as using the desktop view, not the basic HTML though), and they surely have been annoying
the desktop view is obviously not touch-friendly and way too laggy as there is simply too much resource-taking stuff to load on the page
using it just for changing senders is too inefficient..

that'll be awesome if there's an app with this feature
thanks!