MegaN64 by Jeffrey L. Scott (and many others) is an open sourced N64 emulator for Android. ROMs need to be placed by your own and are not part of the download.

The user feedback so far is very different, from to many adverts to non working. Overall a user rating of 4.2/5.0 is the current status.

https://play.google.com/store/apps/details?id=com.mega.n64.emulator