We are building a cross platform mobile application and I am kind of responsible for iOS part. I'm the first one to begin to work on the instant messaging feature, so my decisions will affect my colleagues who develop Android and Windows Phone parts. And I'm stuck with the question how to properly indicate the message is sent, received, and (may be) seen?
I know that there is the WhatsApp way one tick sent and two ticks received, but this kind of mis-leading users to think that one tick is for received and two ticks for seen. I don't want this mis-leading but I also cannot tell how much damage this will do. I am open for suggestions in this matter.