Hi,
My name is Pedro and II have 4 Years on Mobile Development both on Native Android Apps and Cross Platforms. I've been developing Apps around system managements (back-office access), connected with web services, consuming web APIs and apps applying algorithms for different contexts. If you're interested we can talk about it later.
Depending on kind of project you want to be developed, The milestones may differ on what you want. First of all we need to discuss about the architecture of that application and what should be the functional requirements. After this first milestone usually I ask between 10%-30% of the project offer. Later, the next milestone it's when I start the development and deploy the first release, denoted as staging (not before the approval of the UI/UX validation of the client). Finally, we need to test and fix any issue before deploy it as production.
I hope we can talk soon.