I work with mobile dev (among other things).<p>When you update your iPhone, you can&#x27;t &quot;unupdate&quot; it, Apple after a while always deletes the certificate of all versions that aren&#x27;t the current, and the installer always check the certificate before installing (this also means you cannot install iOS without internet).<p>Xcode, also checks the iOS version, and its own version, some versions of Xcode are tried to specific iOS versions... thus if you keep updating your iOS, you will have to update your Xcode.<p>For some reason, completely unknown to me, Xcode is ALSO tied to OSX version, For example Xcode 6.3 requires a OSX version more than Xcode 6.2, despite having no huge differentes between the two and Xcode 6.3 don&#x27;t requiring any new OS capabilities that Xcode 6.2 didn&#x27;t already used anyway.<p>But every time you update OSX and Xcode, not only they sometimes explicitly require a new machine model, but they also get increasingly more inefficient, using more and more RAM and CPU to do the same things.<p>Since right now, I am very low on money, this means I am stuck using Xcode 6.2, and trying to not misclick anything when I plug the testing devices and iTunes nag me to update them... because if I allow them to get updated, I will have to upgrade Xcode, OSX, and the entire machine, and right now sometimes I can&#x27;t afford even food, affording a entire machine (specially with our currency getting completely broken and being only 25% valuable as it was supposed to when designed, comapred to USD).