Open an old version after close the current version of my app

Hi folks!

I was developing my app months ago, but I had to stop the development … months later I continue my development and at the moment to compile and check it in my phone it opens good but if I close the app the reopen again it open an older version and it always open the same old version. what’s happing with my app?

Any help or clue would be so great

thanks!