Consumers wagered a total of $1.39bn (£1.13bn/€1.32bn) on sports via mobile in April, down from $1.63bn in March of this year.
Gross gaming revenue from mobile sports betting for the month amounted to $104.1m, compared to $104.1m in the previous calendar month.
Flutter Entertainment-owned FanDuel Group remained the runaway leader in the market with $63.6m in revenue from $599.5m in wagers.
DraftKings followed in second with $19.6m in revenue off a handle of $327.1m, with Caesars Sportsbook, which posted revenue of $11.8m after taking $215.7m in bets, third.
BetMGM was next after reporting $5.0m in revenue from $142.2m in total wagers, then Rush Street Interactive with $1.8m in revenue and a $38.0m handle.
PointsBet posted $1.5m in revenue and reported a handle of $53.2m, while WynnBet had $518,705 in revenue off $9.4m in player bets, and Resorts World $335,808 worth of revenue from a $5.8m handle for the month.
The latest monthly figures come after research from mobile gaming customer acquisition company Betting Hero last month suggested mobile sports betting players in New York use an average of 3.3 apps to place bets, compared to 2.8 in New Jersey.
Turning to operators, 63% of sports bettors included DraftKings in their lists when asked to name as many real-money online sportsbooks as they could, slightly ahead of FanDuel at 58%.
DraftKings was also named as the favourite sportsbook of 29% of customers, followed closely by FanDuel at 28%. BetMGM and Caesars were the third and fourth most popular, scoring 12% and 10% of the vote respectively.