When I worked solely in mobile, I mainly worked on new projects. Of the many companies I worked with, very few, only about 10%, used Agile. Did it matter?
On the one hand, we have a few Agile tech speakers and consultants who will tell you if you don’t do it their way you’re stupid or incompetent. On the other we have people such as Jeff Patton, who previously won Agile Alliance’s Gordon Pask Award for contributions to Agile Development, saying common Agile practice isn’t for startups. Jeff’s article is thought-provoking because he says, for many startups, learning velocity is more important than delivery velocity.
Martin Fowler has an related article where he says “You don’t do agile or lean you do agile and lean”. I am not sure this is always true as, in practice, Agile invariably results in a significant upfront investment in additional unit testing – but I suppose it strictly need not when mixing Agile and lean.
You really need to consider your project. Is learning velocity important? Agile and better testing came out of a time when there were huge projects that were failing. Is your mobile project that huge/complex (it can be) or are you over-engineering? What’s your initial budget? What’s the anticipated lifespan of your software? Will the code ever have to be handed over to others to continue to develop? Is the project mission critical? How many people will be developing the project and how experienced are they? How much do you trust your current development process if you have one? How quickly do you expect things to change and by how much? Answering some of these questions might help you decide how much Agile matters for your project.