Google has changed the file size limitation for APKs submitted to Google Play, as developers can now upload files of up to 100MB in size. The change comes as developers continue to build richer apps and games, and need to include more along with them. Previously, Google had file sizes limited to 50MB, which was less than ideal for developers.
This means developers can publish APKs up to 100MB in size, and users will see a warning only when the app exceeds the 100MB quota and makes use of Expansion Files. The default update setting for users will continue to be to auto-updating apps over Wi-Fi only, enabling users to access higher quality apps and games while conserving their data usage.
However, Google does warn developers that just because they can make apps bigger, doesn't always mean they should. With mobile data connectivity, mobile data caps, overall app performance and install time listed as caution areas, Google wants to make sure developers are using the increased file limitations for the correct reasons.
Source: Android Developers