Carlin,
If the issue is just that the "whites" aren't white enough, but are still true whites, then that's just an exposure problem. Find one of your software programs and then find something called "brightness" or "exposure" and then bump it up, until the whites are clean.
Generally, shooting outdoors, the shadow will create a blue-ish or cyan-ish caste too, so if you see that, either add a bit of yellow, or if cyan, add a bit of red, which has yellow in it and THEN increase the brightness or exposure.
If you're just using your phone, don't worry about RAW files, you're phone won't produce them.
Hope this helps!
You can send me any files that you have and I'll fix them, if the image has a real white in them,
email me privately and I'll give you my address,
Rich