Hi there and thanks for your question!
Regarding the level of effort to implement and configure Target in-app, follow the steps and refer to the helpful links and resources listed within the Adobe Target Product documentation on Target for Mobile Apps.
We strongly recommend that you implement Target using Adobe's Dynamic Tag Management, a free Core Service offering that can be used to quickly adapt your Target implementation as needed. For more information, see the Dynamic Tag Management documentation.
First time implementation for devs who specialize in iOS and Android should be able to work with the following documentation. You can also post in this thread in the forum to get in touch with the other devs on that thread who have implemented Target in-app. You might also find this thread helpful for your Android implementation.
Hope this helps!