Version 1.0 had a bug where if you met your mother in the evening, the game would crash. However, as long as you didn’t take that route, your game should be fine, and you can stick with 1.0. There’s no reason to update until I release 2.0.
In the most recent 1.5 update, I improved the photos in the scene where you meet your mom for the first time (both morning and evening scenes). The quality jump was so significant that it warranted an update.