Many Universities have Pre-application forms (Electronic or by email). You can submit details like GPA; Courses completed, GRE, TOEFL Scores, Research interest, a brief introduction about yourself, etc. It provides useful information about your profile to the admission committee. There are no fees for pre-application, and official transcripts and letters of recommendation are not required. If admission committee like your profile they will encourage you to apply officially!
Pre-Application Forms for some Programs:
When you send information during pre-application you need to be serious and treat it as official application (even if you think you have a strong profile for that college).
Note: Not all colleges offer pre-application evaluation. Some colleges will not respond if you try to contact them about your profile/credentials. Each department receives thousands of applications and it's really not possible to evaluate each application (maybe at some point it will be done using artificial Intelligence!).