Online sportsbooks usually offer the same number of betting markets across desktop and mobile. Some of the most popular sports for US bettors include basketball (NBA and college), football (NFL), baseball (MLB), hockey (NHL), Soccer (MLS), NASCAR, MMA, boxing, golf, and tennis.
It's very likely that you have content control switched on in your network settings, meaning that you won't be able to access certain sites which have an age restriction, such as gambling sites, over mobile data.