Become independent
Ideally, it should not matter whether your app is getting its data from a local stub, a Mobile Backend as a Service (MBaaS), a third party API, or your own API. This is very easy to accomplish. You just need to realize that it is important to separate the different concerns and that implementing contracts matter.
Another lesson learned is that you cannot always trust third party services. You must have heard about Parse. It used to be of the most promising MBaaS and a lot of app developers were depending on it to store their app data in the cloud. Recently, they announced that they will shut down their business, which frustrated a lot of developers. Fortunately, Parse has created an open source version of Parse Server. Anyhow, it nicely illustrates what I am trying to say here. Make sure you do not go out of business even if one of your key partners does.