There is PS Express that can smooth the image, but you won't get a clearer picture. You cannot enhance a pixelated picture to a clear one simply because the information has been lost already.
For example, let say that your old phone took a 320x240 pixels pictures. That gives you 76800 pixels to compose the image. There is not way to enhance that image to a 1024x768 format to have it crisper. Only thing that will happen is that each original pixel will be duplicated to be able to fill the 1024x768 grid.
Only possibilities are denoising, smoothing and sharpening to have kind of a better looking picture. But that's about it and results may vary from one picture to another...
If your old pictures are of a good size (like a 2MP and above), there is still hope to make them look better even if you loose a little bit of resolution..
Play around with PSExpress, it's free and can do some small miracles
VicoPad addict!