<P> BaaS providers have a broad focus, providing SDKs and APIs that work for app development on multiple platforms, such as iOS, Android, Blackberry, Windows Phone, HTML5, and others . </P> <P> BaaS providers generate revenue from their services in various ways, often using a freemium model . Under this model, a client receives a certain number of free active users or API calls per month, and pays a fee for each user or call over this limit . Alternatively, clients can pay a set fee for a package which allows for a greater number of calls or active users per month . There are also flat fee plans that make the pricing more predictable . Some of the providers offer the unlimited API calls inside their free plan offerings . While BaaS is most commonly offered as a commercial service, Open Source options are available . </P> <Ul> <Li> Kumulos </Li> <Li> Azure </Li> <Li> Backendless </Li> <Li> CloudBoost </Li> <Li> Convertigo </Li> <Li> Firebase </Li> <Li> Oracle Cloud </Li> <Li> Red Hat </Li> <Li> MongoDB Stitch </Li> </Ul>

Mobile backend as a service (baas)