Leaflet is a good alternative if you have a postgres sql database to host the openstreetmaps database. You can’t host it in anything else.
This google plugin is really the only viable alternative because if you use googles .js api you have to pay but via their mobile sdk you don’t and this plugin uses the sdk’s and attempts to give us something very similar to the google.maps.js. Mostly it works pretty well but there are serious bugs that the developer just refuses to see/address (plus he has a reputation for being an ass which makes one not want to work with him).
At some point, apple will open up Apple Maps to the mobile world.