Founder of Backpack Media, a mobile development consulting company. Host of 'Code Break' podcast. Passionate about mobile development and automated app deployments.
These tools are usually good for getting started if you don’t have the skills. As you gain traction you should look more into hiring a developer. If using one of the tools I’d make sure that it will be easy for someone that can code to jump in and make needed changes.
Personally I have never seen anyone do this nor do I think it is particularly necessary. You do want to make sure you check what your app does in a paused state (incoming call, app switching, rotation) if you need to save data or are showing sensitive user data.
There are two ways to do this: You can allow customers to control 2 channels for free and then if you want to more control, the customer pays. Another way is to start with 7 days free fully functioning but have an alert that tells them that you only get to keep 2 channels after the 7 day period is over. I'd be happy to speak with you in more detail on this.