iMessage is one of those things that Apple users have long lorded over their Android counterparts.
Various alternatives on Android have popped up but none have really had any staying power.
That could change with RCS or Rich Communication Services, especially now that the four major US carriers are promoting their own RCS-based system.
Android users might not have to wait for all those pieces to fall in place and can enable RCS on their phones, provided they are willing to jump through some hoops to do it.
RCS is being billed by its proponents, which is primarily Google, as a true SMS replacement (though still not encrypted) that gives it iMessage-like features such as typing and seen indicators, multimedia, and more.
Google has tried getting carriers to support the new technology, as it needs to be supported on the network as well, with very little success.