Is there any way to develop iOS apps on a MacPro 2,1 in 2019?
Is there any way to develop iOS apps on a MacPro 2,1 in 2019?


No. I'm afraid you've bought yourself a boat anchor. Developing iOS applications requires you to run a current version of XCode, which in turn requires a current version of macOS.

The MacPro2,1 was produced between mid-2007 and early 2008; the processor in this machine does not support some instructions which are used in current versions of macOS. There is no known way of working around this, and hobbyist projects to enable the use of macOS on unsupported hardware have abandoned all attempts to provide support.