Recommendations for Top Mobile DSPs to Boost New User Acquisition and In-App Purchases

I've had considerable success driving a positive ROI for in-app subscriptions of a meditation app using Apple Search Ads and Google's UAC. To diversify beyond these platforms, I am seeking suggestions on the best mobile Demand-Side Platforms (DSPs), both managed service and SaaS models, that can help with new customer acquisition and increase in-app purchases. Any recommendations would be highly valued.