Mcpe just went away?

I wanted to play minecraft on my cell phone today and have been playing it almost daily for a few weeks now, when I started the app it said that I could not be sure that I had minecraft from the playstore (I bought it from the playstore). So I deleted minecraft and downloaded it. I opened minecraft and reset everything according to my settings. Then I wanted to open my world but there was none. Not with external and not with applications.

You have to restart it

Restart what? Minecraft? I've been too often

Was the location on external?

No

Then you deleted the worlds including the app

Always set to external