With recent advances in mobile technology, mobile devices have emerged from a luxury to a necessity in our daily lives. App development has been growing into a fast-paced market with volatile requirements. From a software developing point of view, responsive and adaptable software process models are advised to cope with such competitive markets. Over the last decade agile and lean methodologies have become very popular for software development in general, but there has only been limited research about the applicability of these methods in the area of mobile applications. This study aims to address the identified research gap and drafts a lean-agile process model that can compete with the requirements of today´s market. Our model ALP-mobile, an agile and lean process for mobile app development, combines elements of Scrum, Kanban and eXtreme Programming (XP). We drafted our model based on previous work and pilot interviews. We then presented it to multiple mobile-app-centric companies in Austria for an initial validation of strengths and weaknesses by industry experts. Our study shows large support and potential for our model among the interviewed experts calling for further increments and practical evaluation in future research.