Could someone help explain why "uses" is wrong? I know that "using" is the right one and "uses" is wrong but I couldn't find the reason or the supporting grammatical rules that explain why it is wrong.
You are only allowed one actual verb per clause -- only one word carries the tense. 'Is' and 'uses' are both verbs (present tense). 'Using' is a participle which can be used with a form of 'be' such as 'is' (present tense) to form the progressive aspect. 'Uses' would have to be used alone, forming the habitual present tense.