I have a Lenovo TAB 2 A10-70F and lately I'm getting pop up ads when I open apps like Instagram, Twitter and Hulu. I've run scans and nothing is found. I've also looked through my apps and nothing stands out. Has anyone else experienced this?

Clear caches for each app & check each apps permissions. Settings>Apps>App Name, also check Settings inside each app by opening the app, some apps offer user controls. Called settings, options or preferences usually.

Otherwise contact each app's Support, found in the App>Help or About, or via the Google Play Store.

Or if this is via a browser, check the browser settings, which often have pop up & ad blockers.

But it shouldn't be due to the device vs. apps or OS settings.