It sometimes happen that after a few years, an app is stable enough that it gets into hibernating mode. Though it’s used and useful, there are no changes to it and it happily runs its life. Then, after a while, someone decides to add some new features again. Apart from simple things such as locating the sources, one of the most important thing is to be able to build the app. Though it may seem trivial, there are some things to think about. Here are some advices on how to make apps that can