Direct carrier billing provider Centili recently announced that it reduced its Android in-app payments library to 50kb, according to a press release. 

Centili said at this size its Android library SDK is the smallest on the market. This development will enable content providers and merchants to further improve user experience and conversion rates as they monetize digital goods via Android apps, according to the announcement.

Centili said in the announcement the SDK size is important because lower-end smartphones don't offer massive storage space. 

"Some app stores also impose size limits, meaning that for bigger apps, access to these stores will be limited," the company said in a statement. "Lower space consumption by the billing library also means developers get more space for the core app features."