That is true.
The app doesn't save the last state of the project on activity destroy.
1) you draw
2) you go to other activity (by clicking "Home", having incoming call or other...)
3) you run some more apps
4) android destroys the PS Touch activity to free some RAM (standart thing)
5) you start the PS Touch again and see that your work is lost.
But easily the most frustrating part of Photoshop for smartphones is that it tends to close quickly. Switch to your browser or homescreen for more than a minute, and Photoshop will need to reboot. That's not a big deal in and of itself, but it will also lose whatever changes you've made to your open photo without saving, no matter how long you've been working on it. This behavior will teach you to save early and often. This may not be avoidable, considering the huge memory footprint (it'll easily eat up 100MB or more) but the app should have some kind of auto-save feature in place.
More info for your developers team: http://developer.android.com/training/basics/activity-lifecycle/stopping.html
Please fix it.
I purchased the app and as I mentioned in my previous reply, the app crashes quiet often which is very annoying especially when you have a lot of layers and you have to start everything from a scratch. No save button or autosave function. In fact it crashes every time when I try to import photo layer with large size image or when downloading large image from Cretive Cloud. I`m using the app on iPhone4 and iPad Mini, and the problem is with both devices. Taught the problem is with my devices, but asked few friends to try the app and they have the same problem on iPhone 5/5s, 4/4s. I just rated the app with one star and comment in the US app store. For large company like Adobe, you left the things half way and your developers didn`t do their job properly! If it was single developer would get 3 -4 stars and a comment with recomendadtions. But Adobe... you get one star and dissapointed user that spend 15$ for app that is crashing. Awesome intuitive interface... but unusable. Well done Adobe!