Clean Up Apps For Tablet?

Samsung partnered with Cheetah Mobile with that "Smart" Cleaner app, and quite bluntly, it's crap. Just like all Cheetah Mobile products. That said, the best cleaning app available is SDMaid and its unlocker to enable the pro features.

The "apps may not be optimized for this device" warning is because the apps in question are written with smartphones in mind and may not display correctly on the tablet's screen. Usually however this fact does not impede their usefulness. SDMaid Pro if I recall doesn't have this optimization issue.

One thing to keep in mind is that the hardware is likely the largest contributing factor regarding your wife's tablet being reduced to a "walking pace". If it's an older tablet, its processor is going to have to work harder to do its job, and the tablet itself is likely to have less RAM available to do the job with. Case in point: the US Samsung Galaxy SIII used a 1.3GHz dual-core processor and had 1.5GB of RAM. The next year, the US Galaxy S4 switched to a 2GHz quad-core processor and increased the RAM to 2GB. The increase made the S4 scream compared to the SIII. The Galaxy S6 however puts both to shame in the hardware sweepstakes. It has an octa-core processor (four 2.1GHz and four 1.5GHz cores in a big/little setup) and 3GB of RAM, allowing it to handle more. So if your wife's tablet is some three to four years old, it may be time to consider getting her a new tablet.