Problem with back button

[gianluca78]

Hello Dimitris,
We have discovered a new bug on on every device with the back button (verified on both a Samsung S4 and ZenPhone 5 with Android 4.4.2)

Please follow the following step to reproduce it:

1. login with the user credentials (for instance "gianlucamerlo", "testtest")
2. select a children
3. go back to the children screen
4. logout
5. click on the physical back button of the device

Users are still able to navigate within the application after this error, so they thought to be still connected. Moving in the various screens, sometimes some json code appears.