We say might because the PlayStation Access video mentioning PS Plus games for April is no longer available and we didn't see it with our own eyes.
PlayStation Access published a video earlier today which mentioned April's PS Plus games will be Uncharted 4 and Dirt Rally 2.0.
Apparently, someone pushed the publish button a bit early on the YouTube channel because the video is now listed as private. The video was originally put up as unlisted, according to resetera, which got the information off reddit.
So, it looks like those might be your two free games on PS4 for the month of April. New releases occur on the first Tuesday of the month, so we expect the games to be made available starting April 7.
We'll know for sure if these two games are indeed the freebies either in the next few days or sometime next week.
Shadow of the Colossus and Sonic Forces are currently available as yourPS Plus game for March.