[Q] Missing apps and accounts

[shantur]

Hi guys,

This morning i tried to open XDA app on my Vipers 1.6.3 powered Sensation and it said the "App is not available" or something similar.
I tried to see if the app is there in Apps under settings and to my surprise the app was not there as well.

Later the phone automatically rebooted and now i am missing all the accounts.

Has anyone faced anything similar? Is internal memory going bad?
Any tools to test internal memory?

Thanks,