Pure keylogging without screen capturing is not very common for Android malware. There are several reasons for this, starting with the fact that, in most cases, it is just not needed, and also because of the peculiarities of data input on mobile devices. Sometimes high-profile spying malware implements it in a pretty creative way. For example, it is possible to keep track of screen touches and match them against a pre-defined map of coordinates to deduce the keys pressed.
An example of a family implementing it is BusyGasper, which is a backdoor malware.
